The invention discloses a power enhancing device which comprises a plurality groups of strong magnetic blocks, wherein each group comprises a left strong magnetic block and a right strong magnetic block which are repelled mutually; the strong magnetic blocks are fixedly connected with sliding structural members; the strong magnetic blocks and the sliding structural members are freely mounted in a shell in a sliding manner; the sliding structural members are hinged to push-pull shafts; the push-pull shafts are hinged to force output crankshafts; the strong magnetic blocks and the sliding structural members move left and right to drive the force output crankshafts to rotate; the force output crankshafts are mounted in the shell through bearings and are connected with force output shafts; magnetism shielding middle shafts are mounted in the shell through bearings; specially-shaped magnetism shielding plates capable of shielding magnetic repulsion force are fixed on the magnetism shielding middle shafts and are positioned between the two strong magnetic blocks of the same group; the left ends of the magnetism shielding middle shafts are connected with force input shafts, and the magnetism shielding middle shafts rotate to drive the specially-shaped magnetism shielding plates to rotate; the repulsion force in certain strong magnetic block groups is shielded, and the repulsion force in the rest of the strong magnetic block groups is not shielded and do work. The power enhancing device has the benefits of simple structure, convenience and safety to use, low manufacturing cost, high power and good power enhancing effect.