The invention belongs to the relevant technical field of obstacle-crossing robots and discloses a planet wheel type obstacle-crossing robot suitable for a rotating stair. The planet wheel type obstacle-crossing robot comprises a vehicle body, a front driving set, a rear driving set, a front hinging shaft structure and a rear hinging shaft structure. The front hinging shaft structure and the rear hinging shaft structure are connected to the reverse front end and the rear end of the vehicle body correspondingly. The front driving set and the rear driving set are connected to the front hinging shaft structure and the rear hinging shaft structure correspondingly. The rear hinging shaft structure comprises a vehicle body rear supporting seat, a horizontal hinging shaft, a hinging frame, a vertical hinging shaft and a rear driving set supporting seat. The vehicle body rear supporting seat is connected to the vehicle body. The rear driving set supporting seat is connected to the rear driving set. The two ends of the horizontal hinging shaft are hinged to the vehicle body rear supporting seat and the hinging frame correspondingly. The two ends of the vertical hinging shaft are hinged to the hinging frame and the rear driving set supporting seat correspondingly.