A preparation method for a temperature-responsive light reflecting coating is provided comprising: forming a main chain cholesteric phase liquid crystal polymer by a polymerization reaction between an acrylate liquid crystal and an amine, and coating the main chain cholesteric phase liquid crystal polymer on a substrate to form a light reflecting coating, wherein the acrylate comprises a chiral acrylate, and the reflection wavelength of the reflecting coating is determined by the content of the chiral acrylate liquid crystal and the polymerization degree of the main chain cholesteric phase liquid crystal polymer formed. The method may further comprise cross-linking the main chain cholesteric phase liquid crystal polymer to obtain a polymer network so as to form a solid coating. The present disclosure further provides a temperature-responsive light reflecting coating. The preparation of the main chain cholesteric phase liquid crystal polymer of the present disclosure requires only a simple thermally-driven polymerization reaction.