The invention discloses an auxiliary operating arm for medical operation. The auxiliary operating arm for the medical operation comprises a fixing mechanism, an adjusting mechanism and a supporting mechanism; the supporting mechanism comprises a supporting seat, and installation plates are arranged on two sides of the supporting seat; the adjusting mechanism comprises an installation seat, the bottom of the installation seat is in cottage grafting with the supporting seat through a connection shaft, and a supporting arm is rotatably connected to the upper end of the installation seat; and supporting mechanism comprises a supporting plate, the supporting plate is rotatably connected with the end, away from the installation seat, of the supporting arm, an angle adjustment mechanism is arranged at a joint of the supporting plate and the supporting arm, connection plates are rotatably connected to two sides of the supporting plate, and placing plates are rotatably connected to the bottomsof the connection plates. When long-term operation is carried out on the auxiliary operating arm for the medical operation, doctors can place arms on the placing plates for supporting, the stability of the arms and operation accuracy can be improved, physical consumption is reduced, the operation efficiency is greatly increased, angles of the placing plates can be adjusted, and operation is convenient.