Steel cylinder plate type bottom closing machine capable of rapidly replacing combined die

The invention discloses a steel cylinder plate-type bottom closing machine capable of rapidly replacing a combined die, and particularly relates to the field of steel cylinder machining, the steel cylinder plate-type bottom closing machine comprises a bottom closing machining table, the inner wall of the bottom closing machining table is rotatably connected with a clamping wheel rod, and the outer surface of the clamping wheel rod is fixedly connected with a hollow gear; when steel cylinder molds with different diameters are inserted into holes formed by the clamping type attaching block and the positioning storage frame, the clamping type attaching block is pressed to move outwards, the clamping type attaching block and the positioning storage frame form an expansion state through the air pressure pad, and then the steel cylinder molds with different diameters are installed. The clamping type attaching block is extruded to drive an outer sliding rod to move along the inner wall of a first clamping block, an