This paper presents a design method and its implementation of an automatic weighing system based on CAN fieldbus in process control of industry. First, the general situation of fieldbus and advantages of CAN bus are introduced. Then the mechanical configuration of a glass weighing system is designed and the interface circuits of its control system based on CAN bus network is implemented. Eventually we introduce the software design of the control system and apply it into the real system. The running result of the industrial system based on the automatic CAN bus control proves the efficiency and reliability of the system design.