In this paper, polyamide thermoplastic elastomer (PEBA) phase change material with ε-caprolactam, adipic acid and polyethylene glycol was prepared by one-step melt polymerization. FT-IR, DSC, TG and SEM were used to analyze systematically structural characteristics, phase transformation behavior, heat storage properties and thermal performance of polyamide thermoplastic elastomer phase change material. The results indicate that phase transition temperature, phase change latent heat, thermal stability and phase change material fragility increase significantly when the ratio of long chain and short chain (the mass ratio of polyethylene glycol and caprolactam) of polyamide thermoplastic elastomer phase change material induces.