Abstract: Flexible phase change materials (FPCM) are widely used in the field of human thermal management and temperature control due to their latent heat energy storage and flexibility characteristics, which not only enable efficient energy storage, but also closely adhere to the surface of objects. In this study, a composite phase change material (OM16) was prepared using physical blending of olefin block copolymer (OBC) and hexadecane microcapsules (M16). The results indicate that OM16-1.2 prepared in a 1:1.2 ratio exhibits certain flexibility at low temperatures, with a phase change enthalpy of 85.45 J/g and a phase change temperature of 16.97 °C. After 100 cycles, the phase change enthalpy decreased by only 6.59%, demonstrating excellent cyclic stability. Additionally, it maintains good thermal stability at temperatures below 173 °C. Moreover, 10 g of OM16-1.2 can achieve temperature control for approximately 50 minutes, highlighting its potential for application in cold compress temperature regulation for the human body.