To deal with the real-time and multi-channel data acquisition and supervision of the voltage, current and temperature on the clients' lines in communication system, the design method of the system based on dual CPU structure is described in this paper as well as the hardware composition. The connection of main chips and the software flow are discussed as well. This system has been applied to the supervision of 48 V communication lines in mail system.It shows that the dual CPU plan not only meets the system requirement of massive computation and high real-time and anti-jamming performance but also optimizes both software and hardware design.