Abstract: This paper describes a line-tracking control system of a robot. Under the control of the single-chip microcomputer subsystem, the system can collect,save and process the digital signal from the line-tracking system,then controls the stepmotor through the driving system, and with the system robot can move according to preinstalling tracking.It shows that the system has the characteristics of automatic cut-away, credibility, accuracy and high anti-disturbance ability and so on.and the system guarantees accuracy of the robot moving.