Abstract: Here the electrocaloric effect（ECE） and thermal conductivity of polymer-based electrocaloric（EC） materials are improved by means of the preparation of BaZr_0.2Ti_0.8O₃-P（VDF-TrFE-CFE） nanocomposites. In addition, high-power refrigeration devices based on fluid-solid conjugated heat transfer were designed and numerical simulations were carried out to evaluate the cooling capacity and efficiency. The results show that T-BZT-10%（with a BZT mass fraction of 10%） has significantly ECE and heat transfer performance than that of the base terpolymer. Simulation results about the devices show that at a temperature span of 10 K, a system with T-BZT-10%as the core refrigeration element can achieve a cooling power density of 31.0 W/cm~3 and total cooling power of 1060.4 W（more than a 10-fold cooling power improvement than that of the base EC device） with a COP of 5.2.