The invention belongs to the field of medical instruments and relates to a fixing device, in particular to a limb fixing device for kidney transplantation operation, comprising a base, an adapter chute is rotatably connected to the base, and an arm supporting device is slidably connected to the adapter chute. Both sides of the base are provided with movable sliding grooves which are communicated with the adapter sliding grooves. The arm support device comprises a pair of guide rails slidably connected with the adapter chute, and a slider is slidably connected with the guide rails; One end of the slider far away from the adapter chute is connected with a sliding seat, an upper sliding seat is slidably connected with the sliding seat, a lower supporting plate is connected with the upper sliding seat, an upper supporting plate is arranged above the lower supporting plate, a pair of telescopic rods are arranged on the upper sliding seat, and the telescopic ends of the telescopic rods are rotatably connected with the upper supporting plate base fixedly connected with the upper supporting plate; a support plate is arranged above that base, and a buttock clamping device is arranged on thesupport plate. The invention effectively solves the problems that the arm of a patient is prone to sour anesthesia and the fixation effect of the patient is not good in the operation process.