The invention relates to an ocean platform floating crane 
system provided with a three-level variable amplitude and vibration-absorption hedging hydraulic device. The ocean platform floating crane 
system comprises a boat body, a storage rack, a base, a rotary platform, a 
tower column, a main hoisting mechanism, and three-level variable amplitude and vibration-absorption hydraulic mechanisms. A 
cantilever of the floating crane 
system can control the three-level variable amplitude and vibration-absorption hydraulic mechanisms in a hoisting manner so as to bear a greater load being compared with the conventional 
rope; the 
cantilever of the floating crane system resists swinging and stably controls a pair of symmetrical three-level variable amplitude and vibration-absorption hydraulic mechanisms to play the effect of a buffer; a the interference can be reduced to be minimum by bidirectional 
plunger piston hedging 
speed reduction and three-level buffering so as to play vibration-resisting and vibration-absorption effects on 
impact of sea wind and 
sea waves; and under the condition that a back 
rope is suddenly cracked and the valve of the load is not more than a certain value, a vibration-absorption 
hydraulic cylinder also can play a certain buffering effect so that a heavy object does not suddenly fall off to cause unnecessary financial resource losses and casualties. The ocean platform floating crane system disclosed by the invention has the advantages of compact structure, 
low gravity center, strong wind and wave resisting capability and large 
working space, is very suitable for a 
working environment of an ocean platform, and has very good popularization and application values.