diff --git a/README.md b/README.md
index 09989d4b5..16eaf0437 100755
--- a/README.md
+++ b/README.md
@@ -145,6 +145,7 @@ For previous versions, please read:
 
 ## V3 changes
 
+* v3.0, 2019-12-20, For [#1508][bug #1508], Refactor srs_is_digital, support all zeros.
 * <strong>v3.0, 2019-12-19, [3.0 alpha5(3.0.75)][r3.0a5] released. 115362 lines.</strong>
 * v3.0, 2019-12-19, Refine the RTMP iovs cache increasing to much faster.
 * v3.0, 2019-12-19, Fix [#1524][bug #1524], memory leak for amf0 strict array. 3.0.75
@@ -1541,6 +1542,7 @@ Winlin
 [bug #1506]: https://github.com/ossrs/srs/issues/1506
 [bug #1520]: https://github.com/ossrs/srs/issues/1520
 [bug #1223]: https://github.com/ossrs/srs/issues/1223
+[bug #1508]: https://github.com/ossrs/srs/issues/1508
 [bug #xxxxxxxxxxxxx]: https://github.com/ossrs/srs/issues/xxxxxxxxxxxxx
 
 [exo #828]: https://github.com/google/ExoPlayer/pull/828
diff --git a/trunk/src/app/srs_app_utility.cpp b/trunk/src/app/srs_app_utility.cpp
index 6ea2ba0f8..9c6343860 100644
--- a/trunk/src/app/srs_app_utility.cpp
+++ b/trunk/src/app/srs_app_utility.cpp
@@ -29,7 +29,6 @@
 #include <arpa/inet.h>
 #include <signal.h>
 #include <sys/wait.h>
-#include <math.h>
 #include <netdb.h>
 
 #ifdef SRS_OSX
@@ -1158,17 +1157,6 @@ string srs_get_peer_ip(int fd)
     return std::string(saddr);
 }
 
-bool srs_is_digit_number(const string& str)
-{
-    if (str.empty()) {
-        return false;
-    }
-    
-    int v = ::atoi(str.c_str());
-    int powv = (int)pow(10, str.length() - 1);
-    return  v / powv >= 1 && v / powv <= 9;
-}
-
 bool srs_is_boolean(const string& str)
 {
     return str == "true" || str == "false";
diff --git a/trunk/src/app/srs_app_utility.hpp b/trunk/src/app/srs_app_utility.hpp
index e058e0a93..5e4d09afe 100644
--- a/trunk/src/app/srs_app_utility.hpp
+++ b/trunk/src/app/srs_app_utility.hpp
@@ -640,12 +640,6 @@ extern int srs_get_local_port(int fd);
 // Where peer ip is the client public ip which connected to server.
 extern std::string srs_get_peer_ip(int fd);
 
-// Whether string is digit number
-//      is_digit("1234567890")  === true
-//      is_digit("0123456789")  === false
-//      is_digit("1234567890a") === false
-//      is_digit("a1234567890") === false
-extern bool srs_is_digit_number(const std::string& str);
 // Whether string is boolean
 //      is_bool("true") == true
 //      is_bool("false") == true
diff --git a/trunk/src/service/srs_service_utility.cpp b/trunk/src/service/srs_service_utility.cpp
index 434cd9d4d..e6312d272 100644
--- a/trunk/src/service/srs_service_utility.cpp
+++ b/trunk/src/service/srs_service_utility.cpp
@@ -28,6 +28,8 @@
 #include <net/if.h>
 #include <ifaddrs.h>
 #include <netdb.h>
+#include <math.h>
+#include <stdlib.h>
 #include <map>
 #include <sstream>
 using namespace std;
@@ -48,6 +50,28 @@ bool srs_string_is_rtmp(string url)
     return srs_string_starts_with(url, "rtmp://");
 }
 
+bool srs_is_digit_number(const string& str)
+{
+    if (str.empty()) {
+        return false;
+    }
+
+    const char* p = str.c_str();
+    const char* p_end = str.data() + str.length();
+    for (; p < p_end; p++) {
+        if (*p != '0') {
+            break;
+        }
+    }
+    if (p == p_end) {
+        return true;
+    }
+
+    int64_t v = ::atoll(p);
+    int64_t powv = (int64_t)pow(10, p_end - p - 1);
+    return  v / powv >= 1 && v / powv <= 9;
+}
+
 // we detect all network device as internet or intranet device, by its ip address.
 //      key is device name, for instance, eth0
 //      value is whether internet, for instance, true.
diff --git a/trunk/src/service/srs_service_utility.hpp b/trunk/src/service/srs_service_utility.hpp
index 86a8e85e8..d9896c13d 100644
--- a/trunk/src/service/srs_service_utility.hpp
+++ b/trunk/src/service/srs_service_utility.hpp
@@ -36,6 +36,18 @@
 extern bool srs_string_is_http(std::string url);
 extern bool srs_string_is_rtmp(std::string url);
 
+// Whether string is digit number
+//      is_digit("0")  === true
+//      is_digit("0000000000")  === true
+//      is_digit("1234567890")  === true
+//      is_digit("0123456789")  === true
+//      is_digit("1234567890a") === false
+//      is_digit("a1234567890") === false
+//      is_digit("10e3") === false
+//      is_digit("!1234567890") === false
+//      is_digit("") === false
+extern bool srs_is_digit_number(const std::string& str);
+
 // Get local ip, fill to @param ips
 extern std::vector<std::string>& srs_get_local_ips();