To solve technical problems of small flow measurement and automatic flow regulating in micro fan aerodynamic performance testing system, a micro fan aerodynamic performance test technology based on the flow balancing method is proposed. Based on the principle of the flow balancing method, the characteristics of aerodynamic and flow regulating of the pipe system are analyzed. Because of adopting flow balancing method, the overall impedance of the pipeline system is basically unchanged when switching on different working channels, and the intended flow rate can be obtained by combining different measuring branches. Theoretically, according to the valve switching on or off, the flow rate of one of the parallel measuring branches is either “1” or “0”, thus it is very convenient to obtain the required flow rate by combining different branches. Experiments were carried out, including flow calibration, flow regulation performance tests and aerodynamic performance test for a micro fan. The results show that flow regulation performance of the combination method meets the expectation, and the combining flow regulation method works well in the micro fan testing experiment, which proves the practicability of the flow balancing method for the micro fan aerodynamic performance testing technique.