diff --git a/docs/CHANGELOG.md b/docs/CHANGELOG.md
index db8a18f8..9262a3f3 100644
--- a/docs/CHANGELOG.md
+++ b/docs/CHANGELOG.md
@@ -8,6 +8,7 @@
 - feat: assert python3 package is ready with specified version
 - refactor: build plugin mechanism, cancel automatic installation of dependencies
 - fix: pip upgrade httprunner when installing hrp
+- fix #1352: avoid conversion to exponential notation
 
 **python version**
 
diff --git a/examples/demo-with-go-plugin/proj.json b/examples/demo-with-go-plugin/proj.json
index 03850cc4..fac542f7 100644
--- a/examples/demo-with-go-plugin/proj.json
+++ b/examples/demo-with-go-plugin/proj.json
@@ -1,5 +1,5 @@
 {
     "project_name": "demo-with-go-plugin",
-    "create_time": "2022-06-14T11:34:25.941159+08:00",
+    "create_time": "2022-06-14T13:19:05.262039+08:00",
     "hrp_version": "v4.1.3"
 }
diff --git a/examples/demo-with-go-plugin/testcases/requests.json b/examples/demo-with-go-plugin/testcases/requests.json
index 75c464f9..4c01ec74 100644
--- a/examples/demo-with-go-plugin/testcases/requests.json
+++ b/examples/demo-with-go-plugin/testcases/requests.json
@@ -22,7 +22,7 @@
             "variables": {
                 "foo1": "${ENV(USERNAME)}",
                 "foo2": "bar21",
-                "sum_v": "${sum_two_int(1, 2)}"
+                "sum_v": "${sum_two_int(10000000, 20000000)}"
             },
             "request": {
                 "method": "GET",
@@ -52,7 +52,7 @@
                 {
                     "check": "body.args.sum_v",
                     "assert": "equal",
-                    "expect": "3",
+                    "expect": "30000000",
                     "msg": "check body.args.sum_v"
                 },
                 {
diff --git a/examples/demo-with-go-plugin/testcases/requests.yml b/examples/demo-with-go-plugin/testcases/requests.yml
index 1db4e4d1..5922ab12 100644
--- a/examples/demo-with-go-plugin/testcases/requests.yml
+++ b/examples/demo-with-go-plugin/testcases/requests.yml
@@ -16,7 +16,7 @@ teststeps:
     variables:
         foo1: ${ENV(USERNAME)}
         foo2: bar21
-        sum_v: "${sum_two_int(1, 2)}"
+        sum_v: "${sum_two_int(10000000, 20000000)}"
     request:
         method: GET
         url: $base_url/get
@@ -29,7 +29,7 @@ teststeps:
     validate:
         - eq: ["status_code", 200]
         - eq: ["body.args.foo1", "debugtalk"]
-        - eq: ["body.args.sum_v", "3"]
+        - eq: ["body.args.sum_v", "30000000"]
         - eq: ["body.args.foo2", "bar21"]
 -
     name: post raw text
diff --git a/examples/demo-with-py-plugin/proj.json b/examples/demo-with-py-plugin/proj.json
index 3cb92bd4..e0ae1816 100644
--- a/examples/demo-with-py-plugin/proj.json
+++ b/examples/demo-with-py-plugin/proj.json
@@ -1,5 +1,5 @@
 {
     "project_name": "demo-with-py-plugin",
-    "create_time": "2022-06-14T11:34:26.276891+08:00",
+    "create_time": "2022-06-14T13:19:05.680344+08:00",
     "hrp_version": "v4.1.3"
 }
diff --git a/examples/demo-with-py-plugin/testcases/requests.json b/examples/demo-with-py-plugin/testcases/requests.json
index 75c464f9..4c01ec74 100644
--- a/examples/demo-with-py-plugin/testcases/requests.json
+++ b/examples/demo-with-py-plugin/testcases/requests.json
@@ -22,7 +22,7 @@
             "variables": {
                 "foo1": "${ENV(USERNAME)}",
                 "foo2": "bar21",
-                "sum_v": "${sum_two_int(1, 2)}"
+                "sum_v": "${sum_two_int(10000000, 20000000)}"
             },
             "request": {
                 "method": "GET",
@@ -52,7 +52,7 @@
                 {
                     "check": "body.args.sum_v",
                     "assert": "equal",
-                    "expect": "3",
+                    "expect": "30000000",
                     "msg": "check body.args.sum_v"
                 },
                 {
diff --git a/examples/demo-with-py-plugin/testcases/requests.yml b/examples/demo-with-py-plugin/testcases/requests.yml
index 1db4e4d1..5922ab12 100644
--- a/examples/demo-with-py-plugin/testcases/requests.yml
+++ b/examples/demo-with-py-plugin/testcases/requests.yml
@@ -16,7 +16,7 @@ teststeps:
     variables:
         foo1: ${ENV(USERNAME)}
         foo2: bar21
-        sum_v: "${sum_two_int(1, 2)}"
+        sum_v: "${sum_two_int(10000000, 20000000)}"
     request:
         method: GET
         url: $base_url/get
@@ -29,7 +29,7 @@ teststeps:
     validate:
         - eq: ["status_code", 200]
         - eq: ["body.args.foo1", "debugtalk"]
-        - eq: ["body.args.sum_v", "3"]
+        - eq: ["body.args.sum_v", "30000000"]
         - eq: ["body.args.foo2", "bar21"]
 -
     name: post raw text
diff --git a/hrp/internal/scaffold/templates/testcases/demo_requests.json b/hrp/internal/scaffold/templates/testcases/demo_requests.json
index 75c464f9..4c01ec74 100644
--- a/hrp/internal/scaffold/templates/testcases/demo_requests.json
+++ b/hrp/internal/scaffold/templates/testcases/demo_requests.json
@@ -22,7 +22,7 @@
             "variables": {
                 "foo1": "${ENV(USERNAME)}",
                 "foo2": "bar21",
-                "sum_v": "${sum_two_int(1, 2)}"
+                "sum_v": "${sum_two_int(10000000, 20000000)}"
             },
             "request": {
                 "method": "GET",
@@ -52,7 +52,7 @@
                 {
                     "check": "body.args.sum_v",
                     "assert": "equal",
-                    "expect": "3",
+                    "expect": "30000000",
                     "msg": "check body.args.sum_v"
                 },
                 {
diff --git a/hrp/internal/scaffold/templates/testcases/demo_requests.yml b/hrp/internal/scaffold/templates/testcases/demo_requests.yml
index 1db4e4d1..5922ab12 100644
--- a/hrp/internal/scaffold/templates/testcases/demo_requests.yml
+++ b/hrp/internal/scaffold/templates/testcases/demo_requests.yml
@@ -16,7 +16,7 @@ teststeps:
     variables:
         foo1: ${ENV(USERNAME)}
         foo2: bar21
-        sum_v: "${sum_two_int(1, 2)}"
+        sum_v: "${sum_two_int(10000000, 20000000)}"
     request:
         method: GET
         url: $base_url/get
@@ -29,7 +29,7 @@ teststeps:
     validate:
         - eq: ["status_code", 200]
         - eq: ["body.args.foo1", "debugtalk"]
-        - eq: ["body.args.sum_v", "3"]
+        - eq: ["body.args.sum_v", "30000000"]
         - eq: ["body.args.foo2", "bar21"]
 -
     name: post raw text
diff --git a/hrp/internal/scaffold/templates/testcases/demo_requests_test.py b/hrp/internal/scaffold/templates/testcases/demo_requests_test.py
index dd65d1f0..30d7f022 100644
--- a/hrp/internal/scaffold/templates/testcases/demo_requests_test.py
+++ b/hrp/internal/scaffold/templates/testcases/demo_requests_test.py
@@ -26,7 +26,7 @@ class TestCaseDemoRequests(HttpRunner):
         Step(
             RunRequest("get with params")
             .with_variables(
-                **{"foo1": "bar11", "foo2": "bar21", "sum_v": "${sum_two_int(1, 2)}"}
+                **{"foo1": "bar11", "foo2": "bar21", "sum_v": "${sum_two_int(10000000, 20000000)}"}
             )
             .get("/get")
             .with_params(**{"foo1": "$foo1", "foo2": "$foo2", "sum_v": "$sum_v"})
@@ -36,7 +36,7 @@ class TestCaseDemoRequests(HttpRunner):
             .validate()
             .assert_equal("status_code", 200)
             .assert_equal("body.args.foo1", "bar11")
-            .assert_equal("body.args.sum_v", "3")
+            .assert_equal("body.args.sum_v", "30000000")
             .assert_equal("body.args.foo2", "bar21")
         ),
         Step(
diff --git a/hrp/parser.go b/hrp/parser.go
index 84482e3a..99e4359b 100644
--- a/hrp/parser.go
+++ b/hrp/parser.go
@@ -7,6 +7,7 @@ import (
 	"path"
 	"reflect"
 	"regexp"
+	"strconv"
 	"strings"
 
 	"github.com/httprunner/funplugin"
@@ -66,13 +67,15 @@ func (p *Parser) ParseHeaders(rawHeaders map[string]string, variablesMapping map
 }
 
 func convertString(raw interface{}) string {
-	if value, ok := raw.(string); ok {
-		return value
-	} else {
-		// raw is not string, e.g. int, float, etc.
-		// convert to string
-		return fmt.Sprintf("%v", raw)
+	if str, ok := raw.(string); ok {
+		return str
 	}
+	if float, ok := raw.(float64); ok {
+		// f: avoid conversion to exponential notation
+		return strconv.FormatFloat(float, 'f', -1, 64)
+	}
+	// convert to string
+	return fmt.Sprintf("%v", raw)
 }
 
 func (p *Parser) Parse(raw interface{}, variablesMapping map[string]interface{}) (interface{}, error) {
@@ -203,7 +206,7 @@ func (p *Parser) ParseString(raw string, variablesMapping map[string]interface{}
 
 			// raw_string contains one or many functions, e.g. "abc${add_one(3)}def"
 			matchStartPosition += len(funcMatched[0])
-			parsedString += fmt.Sprintf("%v", result)
+			parsedString += convertString(result)
 			remainedString = raw[matchStartPosition:]
 			log.Debug().
 				Str("parsedString", parsedString).
@@ -232,7 +235,7 @@ func (p *Parser) ParseString(raw string, variablesMapping map[string]interface{}
 			}
 
 			matchStartPosition += len(varMatched[0])
-			parsedString += fmt.Sprintf("%v", varValue)
+			parsedString += convertString(varValue)
 			remainedString = raw[matchStartPosition:]
 			log.Debug().
 				Str("parsedString", parsedString).
diff --git a/hrp/parser_test.go b/hrp/parser_test.go
index ee0b6fb3..ced53b69 100644
--- a/hrp/parser_test.go
+++ b/hrp/parser_test.go
@@ -613,6 +613,8 @@ func TestConvertString(t *testing.T) {
 		{"123", "123"},
 		{123, "123"},
 		{1.23, "1.23"},
+		{100000000000, "100000000000"}, // avoid exponential notation
+		{100000000000.23, "100000000000.23"},
 		{nil, "<nil>"},
 	}
 
diff --git a/hrp/step_request.go b/hrp/step_request.go
index f890a93e..8c4de3a4 100644
--- a/hrp/step_request.go
+++ b/hrp/step_request.go
@@ -125,7 +125,7 @@ func (r *requestBuilder) prepareHeaders(stepVariables map[string]interface{}) er
 		}
 		r.req.AddCookie(&http.Cookie{
 			Name:  cookieName,
-			Value: fmt.Sprintf("%v", value),
+			Value: convertString(value),
 		})
 	}
 
@@ -163,7 +163,7 @@ func (r *requestBuilder) prepareUrlParams(stepVariables map[string]interface{})
 		if len(parsedParams) > 0 {
 			queryParams = make(url.Values)
 			for k, v := range parsedParams {
-				queryParams.Add(k, fmt.Sprint(v))
+				queryParams.Add(k, convertString(v))
 			}
 		}
 	}
@@ -217,7 +217,7 @@ func (r *requestBuilder) prepareBody(stepVariables map[string]interface{}) error
 			// post form data
 			formData := make(url.Values)
 			for k, v := range vv {
-				formData.Add(k, fmt.Sprint(v))
+				formData.Add(k, convertString(v))
 			}
 			dataBytes = []byte(formData.Encode())
 		} else {