A thin displacement driving device includes a first movable plate, a second movable plate, an axial limiting unit, a first actuator and a second actuator. The axial limiting unit limits the moving direction of the first movable plate and the second movable late. The first actuator has a first shape memory alloy wire coupled to the first movable plate, and the second actuator has a second shape memory alloy wire coupled to the second movable plate. Movement of the first movable plate by the actuation of the first actuator will trigger movement of the second movable plate, and movement of the second movable plate by actuation of the second actuator will trigger movement of the first movable plate.