The invention provides a broaching machine special for a horizontal machining air cylinder. The broaching machine includes a machine bed, a hydraulic system, a cutter system, a fixture system, a loading and unloading system, a cooling system, a chip removal system and an electrical control system, the machine bed is connected with the hydraulic system, the cutter system, the fixture system, the loading and unloading system, the cooling system, the chip removal system and the control system, the machine bed is horizontal and rectangular, and a main sliding plate is arranged on the machine bed,and driven by an oil cylinder to move horizontally in the long axis direction of the machine bed; the cutter system includes a broach and a knife holder, and the broach is fixed to the main sliding plate through the knife holder; the cooling system is connected with the chip removal system, and located at the same end of the machine bed; and the hydraulic system is located at the other end, away from the cooling system, of the machine bed, and the loading and unloading system includes a loading and unloading conveying mechanism and a feeding and discharging oil cylinder. According to the provided broaching machine special for the horizontal machining air cylinder, after loading, the position of a machine tool can be automatically aligned, the difficulty of loading is reduced, and the production efficiency of the air cylinder is improved.