Reducer anti-torque structure of medical robot

The invention discloses a reducer anti-torque structure of a medical robot. A positioning shaft is arranged beside a reducer and rotationally connected with a pitching arm; the positioning shaft and a rotary base are fixed; a torsional spring base is installed on the positioning shaft and sleeved with a torsional spring; an inner hook of the torsional spring is connected with the torsional spring base; and an outer hook of the torsional spring is connected with the pitching arm. The torque of the reducer is balanced through the torsional spring, so that on the one hand, a mechanical arm of the medical robot is effectively prevented from sliding off, and the potential safety hazard is eliminated; on the other hand, torque, size and motor power of the reducer are reduced properly, so that the overall size is reduced, and the cost is effectively saved; and meanwhile, after the torsional spring is additionally arranged, when a motor is out of control suddenly, the torsional spring can achieve the buffering functi