The cooking machine is used in food industry, chemical industry. The hemispherical pot is formed by one-time stamping. The inner and outer pot bodies are made of 304 stainless steel, which is acid resistant, heat-resistant and not easy to corrode, and is highly endurable according to GMP requirements. In addition, in order to avoid heat loss, an insulation layer is also arranged in the middle. The insulation layer is made of insulation cotton with good compactness and high temperature resistance, which has good insulation effect and is not hot.