A push message service method and system capable of allowing a service server to develop a standardized push message format to keep up with different Operating Systems (OSs)-based multiple platforms environment or single user account-multiple platforms environment and preventing push messages from being lost is provided. The multi-push message system supporting multiple platforms includes at least one service server which generates a multi-push message including per-terminal granted push tokens and messages (pns) to be transmitted per push server, a multi-push message manager which checks validity of the multi-push message, parses the multi-push message, generates push messages corresponding to types of the platforms of the push servers based on the messages (pns), and sends the push message to the respective push servers, and a push server which transmits the push message to the terminal corresponding to the push token.