The maximum diameter (φ1425) of the built-in pneumatic wheelset turntable is smaller than the rails. No need to cut the rails when installed. The wheel sets can freely enter and exit the turntable through the internal rails of the factory, eliminating the disadvantages of the traditional turntables whose diameter is larger than the rails and need to cut the rails, at the same time with the advantages of no need to reduce the rail load capacity, no derailment and no damage to the tread. During work, the turntable rises 110mm-140mm, achieving clockwise and anticlockwise steering (rotating 90° each time), and completing the turntable reset after steering. Available methods include manual (by foot) control, short-range control, remote control, operation is simple , safe and reliable.