Precise adjusting mechanism for stroke of air cylinder

The invention provides an air cylinder stroke accurate adjusting mechanism, and relates to the technical field of pneumatics. The mechanism comprises a knob (2), the interior of the knob (2) is hollow, the first end of the knob (2) is arranged on the outer side of a piston rod extending out of the first end of a double-shaft double-acting air cylinder (5) in a sleeving mode, and at least one positioning ball clamping groove (8) is formed in the side wall of the knob (2); the sleeve (4) is hollow, the first end of the sleeve (4) is fixedly connected with the first end of the double-shaft double-acting cylinder (5), and the second end of the sleeve (4) sleeves the outer side of the first end of the knob (2); a positioning ball fixing hole (11) is formed in the side wall of the sleeve (4); the first end of the positioning bead (3) is fixedly mounted in the positioning bead fixing hole (11), and the second end of the positioning bead (3) can stretch and retract in the direction perpendicular to the side wall of t