The invention relates to an automatic multiplying power changing device of a
tower crane. The automatic multiplying
powder changing device comprises a load trolley and a lifting hook
assembly, wherein the load trolley consists of a trolley (1), turning wheels (2), a hand grip fixed rod, and a hang grip (3), the lifting hook
assembly consists of an I-shaped connecting rod (4), a
pulley block (5), a lifting hook group (6), the trolley is provided with the two turning wheels (2) used for guiding ropes, key components: the hand grip fixing rod and the hand grip (3) for realizing changing of the multiplying power are arranged on a main beam of the trolley, a reset spring is arranged at a connection position of the hand grip (3) and the hand grip fixing rod, the I-shaped connecting rod (4) connected with the hand grip and the
pulley block (5) are welded on the
pulley block, and the lifting hook group (6) is provided with a lifting hook and the two turning wheels for guiding ropes. The automatic multiplying power changing device of the
tower crane can complete quick and reliable changing of twice multiplying power and fourth multiplying power of the hoisting mode of the
tower crane without the need of manual operation.