<p>Micro flow piezoelectric proportional valve play an important role in the accurate control of thrust in electric thrusters such as electrospray thrusters and hall thrusters. However, the leakage and inability to open due to the micrometer level displacement nature remains a block in front of its reliable using.This study aims to explore the effects of operating temperature and pre-tightening force on the performance of micro flow piezoelectric proportional valves, and guide the pre-tightening force setting and assembly requirements of the valves through simulation results. The research results indicate that the performance of micro flow piezoelectric proportional valves is mainly affected by the operating temperature. When the working temperature is lower than the assembly temperature, liquid leakage may occur,while the working temperature is higher than the set value, it may not be able to open normally. At operating conditions below assembly temperature, excessive pre-tightening force required for valve sealing can cause the valve to remain normally closed at assembly temperature and above. Therefore, it is recommended to assemble at low temperatures. The main factor affecting valve performance is the working temperature, and ensuring the stability of the working temperature of the micro flow piezoelectric proportional valve is a key measure to ensure its optimal performance.</p>