Excavator boom energy-saving device based on sliding pair and gas energy storage and working method

The invention discloses an excavator boom energy-saving device based on a sliding pair and gas energy storage and a working method. The excavator boom energy-saving device based on the sliding pair and gas energy storage and the working method are applicable to an excavator. The excavator boom energy-saving device comprises a hydraulic sliding device arranged between a boom of the excavator and an upper rotary table, and a rope winding convex plate arranged at the tail of the upper rotary table; the hydraulic sliding device comprises a sliding rail and an air cylinder which are arranged on the boom of the excavator, a sliding block is arranged on the sliding rail, a cylinder body of the air cylinder is hinged to the upper rotary table, a piston rod is hinged to the sliding block, and a piston cylinder of the air cylinder is connected with an air bottle through an air pipe. and steel wire ropes connected with each other are arranged between the rope winding convex plate and the sliding block. The excavator boo