According to opening modes of hatches, the hatch cover hydraulic system series can be divided into translation and folding mode. Translation hatch cover through lift-up cylinder to lift the panel of hatch cover in a position of horizontal slideway. Then use gear. Rack or chain, sprocket to translate the cover to the other side, to open the cover. Folding hatch cover is through hydraulic cylinder to lift two blocks of folding covers, and stand them to the other side of opening cover, to open the cover. Control mode is engine local control of manual direction valve, and power supply is to use two sets motor pump units as spare parts for each other. For simple structure, convenient operation, cheap cost, safety and reliable performance, it is widely used for large bulk vessel, containers, etc.