In order to study the effect of liquid filling rate and operating parameters on the performance of micro-channel separate heat pipe (MCSHP),the steady state heat transfer model of MCSSHP was established. Compared with experimental data,the maximum relative error of this model is 7.9%. Based on the model,the effects of refrigerant filling rate,airflow rate and height difference between evaporator and condenser on refrigerant side heat transfer coefficient,pressure drop,heat transfer rate and energy efficiency ratio (EER) were analyzed. The results showed that the optimal refrigerant filling rate of this system was about 80.2%~105.6%,and the corresponding maximum heat transfer rate was 3.75~3.90 kW. With the increase of the refrigerant filling rate,the heat transfer coefficient at the refrigerant side increased first and then decreased,and the system pressure increased with the increase of the refrigerant filling rate. Meanwhile,when the airflow rate at the evaporator side increased from 1 500 m3/h to 5 000 m3/h,the heat transfer rate and EER increased by 100.1% and 92.5%,respectively. When the height difference between evaporator and condenser increased from 1.2 m to 2.4 m,the average heat transfer rate of the MCSHP increased by 9.18%. The research results are valuable for the energy-saving design and operation control of MCSHP.