A lifting device including a body, at least a first support member and a second support member associated with the body, a power source, a platform movable relative to the body between a first position and a second position, wherein the lifting device is configured to receive an object on the platform, and to raise or lower the object between the first position and the second position； and a platform lifting mechanism associated with the platform, configured to lift and lower the platform so as to lift and lower a subject thereon.
