The communication module was designed based on DeviceNet bus technology in this paper, which had the circuit-breaker used in the DeviceNet. So the intelligence of circuit-breaker was improved. Firstly applied PIC18F458 single chip as control chip in hardware design and proposed the power source, dial switch and LED interface circuit design scheme based on DeviceNet protocol specification. Secondly proposed the soft design scheme, included established module and I/O information communication. At last SST-DN3-PCU-1 main station card was 阿applied as network analyzer to analyze the communication data detail.