Engine cylinder block double-layer water jacket and engine

In order to overcome the problems of non-uniform heat dissipation of different cylinders and non-uniform heat dissipation of the upper part and the lower part of the engine cylinder body of the existing engine cylinder body, the utility model provides a double-layer water jacket of the engine cylinder body and an engine, and the double-layer water jacket comprises a water jacket main body, a containing cavity is formed in the water jacket body, a heat dissipation cavity surrounding the containing cavity is formed in the water jacket body, an upper layer water jacket and a lower layer water jacket which are vertically separated are formed in the heat dissipation cavity, a water passing hole is formed between the upper layer water jacket and the lower layer water jacket, and the water passing hole is communicated with the upper layer water jacket and the lower layer water jacket. And the water jacket main body is provided with a water jacket water inlet communicated with the upper layerwater jacket and a water