The invention belongs to the technical field of elevator equipment and relates to an ultra-thin servomotor for an elevator door motor. The ultra-thin servomotor for the elevator door motor solves the technical problems that the design is not reasonable enough and the like in the prior art and comprises a motor casing, wherein a stator is fixedly arranged in the motor casing, a rotary shaft is arranged in the stator in a penetrating manner, a rotor is fixedly arranged on the rotary shaft, one end of the rotary shaft extends out of the motor casing, the motor casing is flat, the stator is shaped like an annular disc body, and the rotor is shaped like a flat annular cover body and is sleeved on the stator. The ultra-thin servomotor has the advantages that 1, the structure is compact, the maintenance and repairing are convenient, the spatial arrangement is facilitated, the mounting of an elevator air-conditioner is facilitated, and the tall elevator car design is adopted; 2, the overall weight is light, the counterweight is reduced, the power of a tractor is reduced, and the operating cost of a driving system is reduced; 3, a magnetic coder is mounted, the connecting structure is simple, and the on-site maintenance is facilitated; and 4, a stator coil adopts the plastic encapsulation process, the gap between a stator winding and the motor casing is reduced, the heat dissipation and anticorrosion capabilities of the stator coil are reinforced.