Abstract: To meet the fresh air load change and energy saving requirements of the energy recovery device, a mathematical model of booster pump-driven loop heat pipe (BLHP), refrigerant pump-driven loop heat pipe (PLHP), and booster refrigerant pump composite-driven loop heat pipe (CLHP) system was established. The relationship of heating capacity, energy efficiency ratio (EER) and temperature efficiency with the temperature difference between indoor and outdoor was studied with R32 as working medium in winter heating condition, and compared with R22. Finally, the operation modes switching condition was concluded and the energy-saving effect of the R32 system was optimized. Results show that the mass flow of R32 and R22 is approximately equal in booster-driven loop heat pipe (BLHP) mode, and the mass flow of R22 is 125% higher than R32 in PLHP mode. The heating capacity and temperature efficiency of R32 is higher than R22 in BLHP mode. When the temperature difference between indoor and outdoor is lower than 27 ℃, the heating EER of R32 is higher than that of the R22 in BLHP mode. The heating capacity, temperature efficiency and heating EER of R32 is higher than R22 in PLHP mode. In R32 system, CLHP mode has better heat transfer capacity and temperature efficiency than that in BLHP and PLHP modes. The EER of CLHP mode is lower than that of PLHP mode, but close to the value in BLHP mode. In the winter condition, when the indoor and outdoor temperature difference is 35 ℃, CLHP mode has a temperature efficiency 163% and 144% higher than that of BLHP and PLHP mode, respectively. Considering the temperature efficiency and system performance, BLHP mode performs better when the indoor and outdoor temperature difference is less than 8.5 ℃ in winter heating condition, yet when the indoor and outdoor temperature difference is greater than 8.5 ℃, CLHP mode is more suitable.