Length-adjustable exoskeleton robot leg structure and using method

The invention discloses a length-adjustable exoskeleton robot leg structure and a using method. The length-adjustable exoskeleton robot leg structure comprises a thigh mechanism and a shank mechanism, wherein the thigh mechanism and the shank mechanism are the same in structure, and both comprise leg shells; sliding grooves are formed in the two inner side walls of leg shells; sliding blocks are arranged on the two outer side walls of adjusting plates; long sliding ways are formed in the two side plates of the adjusting plates; rotating shafts I with rope winding wheels I and rotating shafts II with rope winding wheels II are respectively mounted on the inner side walls of leg shells; rotating shafts I are connected with servo motors; fixing shafts with fixing wheels I and fixing wheels II are mounted on the inner side walls of the adjusting plates; the fixing wheels I are connected with middle rope winding wheels I through ropes I; the fixing wheels II are connected with the middle rope winding wheels II thr