The utility model provides an iron tower hydraulic lifting device includes two foundation framves, suit expansion bracket in the chassis, the interval sets up the pinhole on chassis, the expansion bracket, the chassis that corresponds installation bottom -support beam, and the expansion bracket that corresponds installation upper supporting beam, last first arm -tie and the second arm -tie of setting up of upper supporting beam, the last hydraulic jack that sets up of bottom -support beam. The utility model discloses a pinhole that expansion bracket and chassis interval set up makes the column foot promote step by step, only uses small -size hydraulic jack can realize the promotion of the great stroke of column foot, and use tools is few, and the operating procedure is simple, has reduced the cost of steel pylons maintenance greatly.