The invention discloses a joint simulation method based on a power system and a communication system. The method is suitable for a joint simulation engine, and the joint simulation engine comprises a data interface of the power system, a control module and a data interface of the communication system, wherein the data interface of the power system is connected with a simulation system of the power system, and the data interface of the communication system is connected with a simulation system of the communication system. The method comprises the following steps of after the control module receives data volume through the data interface of the power system, dividing the data volume by the control module through business calculation according to the requirement of the simulation system of the communication system, and sending the divided data volume to the corresponding simulation system of the communication system by the control module via the data interface of the communication system; and/or, after the control module receives transmission delay information and error code rate through the data interface of the communication system, converting the transmission delay information and the error code rate into triggering signal time information and error information by the control module through business operation, and sending the triggering signal time information and the error information to the simulation system of the power system by the control module through the data interface of the power system. The method has the advantage that the accuracy and the trueness of simulation of the power system are accurately reflected.