The invention discloses a propeller especially used for an electric hydrofoil surfboard, The structure comprises a spindle, a bearing, a motor, a mounting base, an impeller, a fin, a positioning axlecarrier, a tail wing. the motor is fixedly and fitting connected with the central side wall inside the housing through a side wall buckle plate, the positioning shaft frame comprises a valve seat, a couling part, a guide plate, a connecting shaft, an insert part, A support bracket is driven by an insert to be connected with equipment to consolidate and support the valve seat, The impeller is movably arranged at the front end of the valve seat by the inner groove and the coupling part, and then the rotational speed of the impeller is increased by the rotation of the connecting shaft and the coupling member to reduce the impact of the underwater pressure, and at the same time, a guide plate directs the impeller to maintain the orientation so as to avoid the distortion of the forced bending moment, thereby improving the stable force of a surfboard on the water surface so as to continuously and steadily operate.