The utility model relates to a lifting mechanism for a lifter, which comprises a three-legged stand, a fixed pulley, two guide pole sleeves, a handle and a hand-operated winch, wherein the three-legged stand comprises lateral uprights; through holes are formed in the lower parts of the lateral uprights; the fixed pulley is arranged at the top of the three-legged stand; the guide pole sleeves are arranged at the lower part of the three-legged stand; two linear bearings are arranged in each guide pole sleeves; the handle is arranged between and connected with the guide pole sleeves; the hand-operated winch is arranged on one side of the three-legged stand; a steel wire rope on the hand-operated winch is wound in the chute of the fixed pulley; and cross rods are connected between the lateral uprights. The lifting mechanism for the lifter has a simple structure and can be used for reducing the friction force generated by a bending moment through the adoption of the linear bearings.