The invention relates to a heavy load salvage wave compensation system of a super large floating crane, which comprises a mechanical system, a hydraulic system, a monitor system, control of a hydraulic oil cylinder, control of an accumulator and the like, wherein the mechanical system consists of a lifting drum, a plurality of sets of pulley, a steel wire rope and a large tonnage lifting hook, the hydraulic system consists of an oil cylinder, the accumulator, the hydraulic oil cylinder and a hydraulic valve, and the monitor system consists of a floating crane body displacement monitor, a floating crane ship body displacement monitor and a floating crane lifting heavy weight displacement monitor. The invention solves the problems that when the super large floating crane carries out heavy load salvage, and at the moment that a heavy weight is lifted out of water, because the heavy weight has large volume, seawater forms an eddy current to enable a floating crane ship body to be inclined and swing, and a lifting weight also swings along with the floating crane ship body and can not be controlled, solves the problems that when a large structure is lifted on the sea, waves influence the floating crane ship body to lead to difficult butting of marine platforms to ensure goods to be safely fall on a ship deck or safe offshore platform installation and allows that the ship has certain inclination to be suitable for tough working conditions of marine operation.