The invention discloses an engine cylinder cover lifting appliance and a locking method. The engine cylinder cover lifting appliance comprises two longitudinal arms, a transverse arm, a transverse supporting rod, long plug pins, a connecting rod I, a connecting rod II, a connecting rod III, an operating rod and side wall rods, wherein the side walls of the lower ends of the longitudinal arms are provided with notches, the transverse arm is inserted into the notches in the longitudinal arms, two ends of the transverse supporting rod are connected with the upper ends of the longitudinal arms ina fastened mode respectively, supporting cylinders are arranged at two ends of the transverse arm, a hinge seat is arranged in the middle of the transverse arm, the long plug pins are inserted into the supporting cylinders, the upper ends of the long plug pins are locked by nuts, the connecting rod I is fixedly connected with the side wall of the hinge seat, the lower end of the connecting rod IIis hinged to the upper end of the connecting rod I, the upper end of the connecting rod II is connected with a long groove in the connecting rod III through a pin shaft, the middle part of the connecting rod III is hinged with the hinge seat, the operating rod is axially limited and circumferentially hinged with the side surface of the connecting rod II, the number of the side wall rods is two, the two side wall rods are connected with the longitudinal arms in a fastened mode, and a handle rod is arranged between the two side wall rods. The machining precision of a hole or a cavity in the sideface of an engine cylinder cover is guaranteed, the lifting is convenient and labor-saving, collision accidents are avoided, and thus the lifting is safer and more reliable.