Abstract: This paper analyzes the RS422 communication structure of the rover payload electric control box system of Chang’e-4 probe, including the current technology and the problems of the RS422 communication. In view of the special feature of the RS422 communication in the system, a communication mode of the time slice management mechanism based on RS422 is proposed. It answers the time response requirement in the RS422 communication, ensures the orderly and effective data transmission and the realization of the RS422 normal communication. This mode is a new attempt of a single-chip microcomputer architecture. The practice shows that the mode can meet the system requirements and can be applied widely.