The present invention discloses a translation type top cover of a grain hopper car. The top cover includes a cover body located at a loading opening of a car body, wherein one side of the cover body is hinged to a crank throw, the crank throw is connected to a transmission shaft rotating in the car body, the other side of the cover body is hinged to a connecting lever, the connecting lever is hinged to the car body, and the transmission shaft is connected to a driving mechanism. The beneficial effects of the present invention are as follows: the top cover convenient to operate is provided to solve the problems of low working efficiency and operation with poor safety in the prior art; when the top cover is in the closed state, a self-locking air cylinder guarantees the vertical locking capacity of the top cover, a longitudinal stopping block guarantees the longitudinal locking capacity of the top cover, and a locking base and a locking rod guarantee the transverse locking capacity of the top cover; and a four-connecting-rod mechanism is formed among the car body, the crank throw, the connecting lever and the cover body to achieve translational opening and closing of the cover body and reduce space required.