In order to enhance the resolution of the flow sensor, a biomimetic hair flow sensor based on bi-stable potential energy adjustment is proposed. The sensor is mainly composed of hair, electrode layer, top structure layer, middle connecting layer and bottom supporting layer. On the one hand, the top structure layer adopts asymmetric comb fingers to realize differential capacitance detection; on the other hand, periodic modulated comb fingers are arranged to realize bi-stable potential energy function of the system. Through the fluid-solid mechanical-electrostatic multi-physical field coupling analysis, the relation of capacitance changing with the air velocity was obtained, and the resolution was better than 0.001m/s. In addition, the potential energy function curve of the system was drawn through the electrostatic field analysis of the modulated comb fingers. Finally, based on MEMS processing technology, a reasonable process was designed and the sensor was manufactured.