The invention provides a resetting structure of a mold ejector mechanism, which has strong reliability and simple structure. The resetting structure comprises a base plate, an ejector base plate and an ejector retainer plate, wherein the ejector retainer plate is supported by the ejector base plate, an ejector mechanism is installed at the upper part of the ejector retainer plate, and a resettingpull rod is connected with an ejector of an injection molding machine. The resetting structure is characterized in that the ejector base plate is provided with an installation hole, the upper part ofa push block assembly with convex middle part is fixedly connected in the installation hole, and the base plate is provided with a through inverted convex support hole; the outer circular face of thelower part of the push rod assembly is matched and sheathed with a separating sliding sleeve, and the separating sliding sleeve is matched with and supported in the support hole; in the joint part between the push rod assembly and the separating sleeve, the push rod assembly is sheathed with a spring, and both ends of the spring respectively abut against the outer circular wall face of the push rod assembly and the inner circular wall face of the separating sliding sleeve; the lower part of the push rod assembly is provided with a central hole, a stop block is installed in the central hole, and the spring is installed between the stop block and the top wall of the central hole in the push rod assembly; a circular slot is surrounded between the push rod assembly and the separating sliding sleeve outside the stop block, and a lock steel ball is arranged in the circular slot; and the peripheral face of the stop block seals the circular slot, and the outer circular face of the resetting pull rod is provided with a semicircular slot in the position corresponding to the lock steel ball.