CAN is the acronym of Controller Area Network, which is called Controller LAN. CAN is a kind of field-bus network mainly used in process detection and control. CAN bus has some special properties, such as serial communication by dual line, powerful capability of error detection and anti-interferring, 1 Mbit/s highest communication speed and 5000 m longest communication distance. CAN also has functions of bus access priority and arbitration. This paper mainly presents its technical features, working principle and applications.