diff --git a/tonesc-red-packet/lib/utils.ts b/tonesc-red-packet/lib/utils.ts
index 8acf3b9..106d884 100644
--- a/tonesc-red-packet/lib/utils.ts
+++ b/tonesc-red-packet/lib/utils.ts
@@ -9,16 +9,27 @@ export function parseAmountToInt(amountStr: string, precision: number): bigint {
   // 例："123.45", precision=2 → 12345n
   // 例："0.00001234", precision=8 → 1234n
 
-  const [intPart, fracPart = ""] = amountStr.split(".")
+  // 去掉正负号处理（如不需要可删）
+  const negative = amountStr.startsWith("-")
+  const normalizedStr = negative ? amountStr.slice(1) : amountStr
 
-  if (fracPart.length > precision) {
-    throw new Error(`Amount ${amountStr} exceeds precision ${precision}`)
+  const [intPart, fracRaw = ""] = normalizedStr.split(".")
+
+  // 关键修复点：允许尾随 0
+  const fracTrimmed = fracRaw.replace(/0+$/, "")
+
+  if (fracTrimmed.length > precision) {
+    throw new Error(
+      `Amount ${amountStr} exceeds allowed precision ${precision}`
+    )
   }
 
-  const paddedFrac = fracPart.padEnd(precision, "0")
-  const normalized = intPart + paddedFrac
+  const paddedFrac = fracTrimmed.padEnd(precision, "0")
+  const combined = intPart + paddedFrac
 
-  return BigInt(normalized)
+  const value = BigInt(combined)
+
+  return negative ? -value : value
 }
 
 export function formatAmountFromInt(value: bigint, precision: number): string {