The invention discloses a method for preventing the piston rod of a hydraulic oil cylinder from self-propelling movement during working. The method comprises the following steps: hydraulic oil is conveyed to an oil inlet in the bottom of the cylinder, enters into a rodless cavity to increase pressure in the rodless cavity, and drives the piston rod and a piston to move towards a cylinder cover in a cylinder tube; and when a locking groove in a sleeve moves to be on the same straight line with a locking hinge pin, a connecting element tightly presses the locking hinge pin in the locking groove, and the locking hinge pin locks the piston rod. According to the method, the structure is simple; the manufacturing cost is low; and the locking hinge pin and the locking groove are matched to lock the piston rod so as to prevent the piston from self-propelling movement due to action of external force during working.