Polymer materials are widely used in life, but most of them are composed of hydrocarbon elements and are flammable, therefore has a potential fire hazard. Reducing the heat release of polymers combustion is the key to improve their fire safety. The exothermic heat release is fundamentally attributed to the diffusion of volatile pyrolysis products of polymers at elevated temperatures and subsequent combustion reactions with oxygen. Therefore, the primary method to reduce the heat release of polymer involves controlling the generation quantity of volatile pyrolysis products, modulating the diffusion rate, and managing the combustion reaction in the gas phase. This paper introduces the research progress of the author team on reducing the heat release of polymers combustion based on chemical and physical routes. These routes encompass three key strategies: ① regulating the carbonization reaction of polymers to immobilize degradation products within the condensed phase region, thereby reducing the release of combustible volatile components; ② optimizing the char layer structure through various methods to enhance the barrier effect and curtail the mass and heat transfer of combustible components; ③ inhibiting gasphase combustion reactions, thereby reducing combustion efficiency. The relationships between heat release and both the polymer structure and char layer structure are discussed, and the mechanisms of thermal decomposition and the formation of highquality char layer are elucidated. These findings may provide valuable insights for the development of lowheat release polymer materials.