Abstract: According to the Guiding Opinions on Accelerating the Intelligent Development of Coal Mines,it is proposed that large coal mines should be basically intelligent by 2025,with robots operating in key underground positions,and intelligent unmanned auxiliary transportation,combined with intelligent control technology and road sensing information formation and feedback technology,multi-sensor information fusion technology,an automatic steer-by-wire system for mine explosion-proof auxiliary vehicles was developed. The composition and implementation method of the steer-by-wire system based on the steering angle deviation PI control technique were introduced in detail. The deviation between the target steering angle and the actual steering angle was used as a signal,and the steering wheel deflection direction and angle could precisely controlled through PI closedloop control,so that the system output could be stable and accurate,quickly follow the command and target turning angle,and then realize the precise steering control of the vehicle′s automatic driving. A simulation test was carried out by building an automatic steer-by-wire platform for auxiliary vehicles. The test results showed that the steer-by-wire system based on the steering angle deviation PI closed-loop control technology responded quickly,the automatic steering error was about 2°,and the overshoot was small. It has realized the automatic steering precision control and automatic correction of auxiliary vehicles,and provided a technical path for the realization of the future of Internet + scientific mining with few people (unmanned) mining.