1. A message publishing method, implemented by a message broker, on a computing device, that comprises at least one actual topic, comprising: separately allocating, by the message broker, a dummy topic for each publisher and subscriber, wherein the dummy topic has functions of searching for a next-hop actual topic, wherein each actual topic has a logical connection with at least one dummy topic or at least one actual topic; receiving, by using the dummy topic corresponding to a first publisher, a message from the first publisher; searching for, according to a routing rule between the dummy topic corresponding to the first publisher and the at least one actual topic, the next-hop actual topic of the dummy topic corresponding to the first publisher; determining, according to a routing rule of the next-hop actual topic, a next-hop topic of the next-hop actual topic; transmitting the message to a subscriber corresponding to the dummy topic when the next-hop topic is the dummy topic; and repeating the determining step when the next-hop topic is an actual topic.