Abstract: A system for substance separation and energy recovery by thermal treatment is disclosed. The system includes a thermal treatment reactor, a circulation piping, a heat exchanger, a discharge pipeline, a latent heat recovering device, a gasifier, and a combustion furnace. The substance is fed into the thermal treatment reactor for heating the treated substance so as to produces a gaseous substance by evaporation or pyrolysis. The treated substance is separated into the gaseous substance circulating between the heat exchanger and the thermal treatment reactor and a residual substance being fed into the thermal treatment reactor. The increased gaseous substance, during the circulation process, is fed into a latent heat recovery device, wherein the gaseous substance exchanges heat with a cold fluid and condenses to release latent heat, forming a liquid condensed substance and a non-condensed substance.