Folding hatch cover is big size cover plate, good strength, few accessories and is difficult to damage; transverse joints w/o squeezer, wheel w/o jack device, closure operation adopts automatic hydraulic principle, simple and reliable collected length and height have wide adaptability not only apply to open-air deck, but also to the middle deck, so it is widely used in ordinary dry cargo ships, multi-purpose ships, refrigerated ships, timber carriers and small-medium-sized bulk carrier. The multi-folding hatch cover to keep minimum stowage space and specific requirements. Leading pair is operated by hinged arms on the leading pair and then sequentially the trailing pair is operated by bell crank arm. Each pair is opened to its vertical position and drawn along the longitudinal hatch way. Sequential operating mechanism secures from malfunction of hatch cover operation.