Wire rope haulage trapped rail car for standard rail is a commonly used auxiliary transportation equipment in coal mine. For the full route trapped standard rail car, the existing turnout can not meet the requirements of the tractor. Therefore, it is necessary to design a special pneumatic turnout for the trapped rail car. In this paper, the mechanical structure and pneumatic control system of pneumatic turnout are designed, and the working process and principle are expounded. The switch realizes the functions of pneumatic track change and track locking, solves the problems of track clamping wheel passing through, wire rope guidance and concealment, and improves the existing technology of trapped rail car.