The utility model discloses an engine air cylinder gasket. The air cylinder gasket is of a four-layer-plate structure and comprises an upper plate, a first middle plate, a second middle plate and a lower plate, wherein the upper plate, the first middle plate, the second middle plate and the lower plate are sequentially connected from top to bottom, the second middle plate is provided with an edge turning structure around an air cylinder hole, the second middle plate is provided with deviation adjusting mechanisms on the two side edges of the air cylinder gasket, and the deviation adjusting mechanisms are of an edge turning structure. According to the engine air cylinder gasket, on the basis of an original three-layer-plate air cylinder gasket composed of the upper plate, the middle plate and the lower plate, the second middle plate is added, and therefore the four-layer-plate air cylinder gasket is combined. Due to the edge turning structure around the air cylinder hole of the second middle plate and the edge turning structure of the deviation adjusting mechanisms on the two side edges of the air cylinder gasket, the heat stress borne capability of the air cylinder gasket is enhanced, the structure is simplified, and meanwhile the whole intensity of the air cylinder gasket can be improved. Through the deviation adjusting mechanisms, the air cylinder gasket can adapt to deformation of a cylinder cover in the stress process, and the whole sealing performance of the air cylinder gasket can be greatly enhanced.