For the development trends and defects of the Water Electrolysis Hydrogen Generation Station (WEHGS), the design of CAN bus distributed network control system based on CANopen protocol is presented. CANopen master characteristics have been analyzed, then the communication implementation of CANopen monitor msater protocol stack, which includes the hardware interface and software design of CAN controller based on the LPC2292, is described. The tested results show that CANopen monitor master meets the requirements of WEHGS.