With the development of computer technology, communication technology and control technology, field bus technology appeared. Field bus technology promotes the development of the instrument , measurement and control system. CAN bus as a field bus, has a lot of advantage such as real-time, high reliability, as well has a lot of applications in the field of industry, medical equipment, and others.For the development of the filed bus, this paper use the CAN bus as the communication bus, select the C8051F040 which has the ability of high speed, high integrity, designed the data acquisition system based on CAN bus.The intelligent data acquisition system consists of PC, CAN-232 node and the data acquisition nodes.By analyzing the protocol of CAN bus ,this paper designed and realized the CAN bus interface function based on C8051F040, then finished the design of the CAN-232 node, fulfilled the data exchange between the data acquisition nodes based on CAN bus and PC.According to the need of this system, this paper designed the circuit of current, voltage and speed acquisition, keyboard and display circuit as well as the circuit of isolation of CAN bus.In the environment of KEIL C51, using the modular design approach, this paper completed all modules, such as voltage and current acquisition module, CAN bus communication module, speed measurement module, LCD module, and keyboard scanning module. Through the arrangement of all the tasks, this paper achieved the requirement of this system.Through the analysis and design of anti-jamming, self-adjustment and the digital communication, the nodes in this system have high intelligence. The application of CAN bus in this system improved the reliability of communication. By modulating the program of this system based on the environment of Visual C++, this paper achieved the function of data recording, data monitoring and alarm.