The operation discloses an auxiliary mechanical arm for a doctor operation. Lower supporting arms are arranged below the mechanical arm. Universal wheels are installed on fulcrums at the bottom of the mechanical arm. An oil cylinder, a cylinder body and lifting vertical columns are sequentially installed above the joints of the lower supporting arms. A front stretching arm is horizontally arranged on the upper portions of the lifting vertical columns. The upper plane and the lower plane of the front stretching arm are fixedly connected with a strip-shaped movable support and a disk rotating support through center fixing bolts. Transverse rails are installed between the disk rotating support. Two transverse rollers are installed in the transverse rails. A connecting rod is arranged between the two transverse rollers. A longitudinal rail is connected to the lower portion of the connection rod through a hanging frame. Two longitudinal rollers are installed in the longitudinal rail. A connecting rod is arranged between the two longitudinal rollers. A movable diamond-shaped frame is connected to the lower portion of the connection rod. The ends of two adjacent edges of the lower portion of the movable diamond-shaped frame are fixedly connected with two semicircular grab hooks. The auxiliary mechanical arm for the doctor operation is simple in structure, convenient and fast to use and capable of saving manpower, and the position is easy to control in the moving process.