The invention discloses a high-power piezoelectric bimorph laminated cantilever type actuator and an actuating method thereof. The device comprises a plurality of piezoelectric bimorphs, an interlayerconnection component and an axial pre-pressure component; a certain positions in length direction of the piezoelectric bimorph are selected as lateral actuating associated positions; each layer of piezoelectric bimorph is fixed to a shaft at each position; two bearings are sleeved on both ends of each shaft, and the bearings at one side of the actuator are fixedly interconnected through a connecting rod with holes, so as to correlate the lateral movement of the piezoelectric bimorphs of each layer; Each layer of piezoelectric double-crystal bimorphs are applied axial pre-pressure by using axial pre-pressure component to increase the actuating stroke; the axial pre-pressure component comprises a micro-bearing, a bearing sleeve with a prefabricated clamping groove and an elastic belt. The invention can improve the output force and the actuating stroke of the piezoelectric bimorph actuator within a narrow space, thereby increasing the output power simultaneously; and it can be used as anactuator of airfoil deflection of a micro-sized aircraft or bionic machine fish-tailing of a bionic machine.