diff --git a/es2panda/lexer/lexer.cpp b/es2panda/lexer/lexer.cpp
index 8b2210e8dc7522cc6477f1a503454097c99fc0ea..6ba93184a8ab0b29a85f653806371e3f17bf61f4 100644
--- a/es2panda/lexer/lexer.cpp
+++ b/es2panda/lexer/lexer.cpp
@@ -304,6 +304,7 @@ void Lexer::ScanDecimalNumbers(bool allowNumericSeparator)
             }
             case LEX_CHAR_UNDERSCORE: {
                 Iterator().Backward(1);
+                isUnderscore_ = true;
 
                 if (Iterator().Peek() == LEX_CHAR_DOT || !allowNumericSeparator || !allowNumericOnNext) {
                     Iterator().Forward(1);
@@ -421,6 +422,10 @@ void Lexer::ScanNumber(bool allowNumericSeparator, bool allowBigInt)
         if (!allowBigInt) {
             ThrowError("Invalid BigInt number");
         }
+        if (isUnderscore_) {
+            ConvertNumber(exponentSignPos);
+            isUnderscore_ = false;
+        }
 
         return;
     }
diff --git a/es2panda/lexer/lexer.h b/es2panda/lexer/lexer.h
index b8302270254e34d7535b8cc14df7819cea242c25..8e56da6ed23d1c25d7e6a9a3cce75474f5087611 100644
--- a/es2panda/lexer/lexer.h
+++ b/es2panda/lexer/lexer.h
@@ -174,6 +174,7 @@ private:
     const parser::ParserContext *parserContext_;
     util::StringView source_;
     LexerPosition pos_;
+    bool isUnderscore_ = false;
 };
 
 class TemplateLiteralParserContext {
diff --git a/test262/es2021_tests.txt b/test262/es2021_tests.txt
index 2c8dfed8b24149b2c67eac579487b02f07f0d9c4..621ccf078c9525179e0288eaf10d6282cf34cd10 100644
--- a/test262/es2021_tests.txt
+++ b/test262/es2021_tests.txt
@@ -1121,6 +1121,24 @@ annexB/built-ins/RegExp/incomplete_hex_unicode_escape.js
 annexB/built-ins/RegExp/named-groups/non-unicode-malformed-lookbehind.js
 annexB/built-ins/RegExp/named-groups/non-unicode-malformed.js
 language/literals/bigint/numeric-separators/numeric-separator-literal-unicode-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-bil-bd-nsl-bd-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-dds-nsl-dds-dunder-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-dd-nsl-dds-dunder-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-dds-nsl-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-bil-nsl-bd-dunder-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-hil-nsl-hd-dunder-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-bil-nsl-bd-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-hil-hd-nsl-hd-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-oil-nsl-od-dunder-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-lol-00-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-hil-nsl-hd-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-unicode-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-dd-nsl-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-lol-01-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-lol-07-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-nzd-nsl-dds-dunder-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-oil-nsl-od-err.js
+language/literals/bigint/numeric-separators/numeric-separator-literal-oil-od-nsl-od-err.js
 language/literals/string/unicode-escape-nls-err-single.js
 language/literals/string/unicode-escape-no-hex-err-single.js
 language/literals/string/unicode-escape-nls-err-double.js