The utility model relates to a chloromethane synthetic waste heat heat transfer device, especially a synthetic cauldron waste heat heating methyl alcohol device in synthetic process of chloromethane. The raw material methanol pump is through the wall connection of liquid methyl alcohol connecting line and heat exchanger hypomere, is located methyl alcohol export on the heat exchanger hypomere outer wall through the gasification section methyl alcohol access connection on methyl alcohol liquid connecting line and the heat exchanger upper segment outer wall, is located to trade the methyl alcohol gas outlet of holding on the ware upper segment outer wall and be connected with methyl alcohol gas buffer tank, the synthetic cauldron of chloromethane passes through the inner bag intercommunication of forming gas connecting line and heat exchanger upper segment, and the heat exchanger upper segment is connected through being connected the compensator with the heat exchanger hypomere, the heat exchanger hypomere is the section that heaies up, and the heat exchanger upper segment is the gasification section. Compared with the prior art, two sections designs of the section that heaies up and gasification section, the sensible heat and the gaseous water -soluble liberated heat of HCL of the make full use of synthetic gas methyl alcohol that gasifies to reach the mesh of practicing thrift steam.