The invention is about a locking device of double capacity compressor. In the invention, after the eccentric sleeve rotates to a right position relative to centrifugal fin along the crankshaft, it will rotate with the centrifugal fin. On the eccentric sleeve, a centrifugal weight part is arranged which can generate centrifugal force by the crankshaft; on the centrifugal pin, a locking pin is arranged for making the eccentric sleeve rotate with the crankshaft; and on the eccentric sleeve, a hanging-joint end is arranged which can hang the locking pin. on the centrifugal pin, a joint lever is arranged which can transfer the rotary force from the crankshaft to the piston, and on the joint lever, the eccentric sleeve is mounted. on the cirumferential surface of the centrifugal pin, a lubricating oil filling part is arranged; The lubricating oil filling part gets the lubricating oil supply by the oil groove and oil channel arranged on the crankshaft. In the structure, because the lubricating oil in the filling part can prevent friction and expansion between the eccentric sleeve and centrifugal pin, the working noise can be reduced.