A message processing method is provided. The method includes the following steps. A message containing flag information is received. The received message containing the flag information is identified. If the message is a real-time message, the message is sent. If the message is a non-real time message, the non-real time message sent from a sender is combined and sent. A message processing system and a message combining device are further provided. Through the method, the device, and the system, the real-time messages are immediately delivered to subscribers, various types of non-real time messages are combined, converted to one or more messages, and delivered to the subscribers according to time assigned by the subscribers, thereby clearing a message space, and preventing interference to the subscribers.