A biaxial resonant micro accelerometer with high sensitivity and low cross coupling is designed in this paper. The I-beam is used as the decoupling beam, and the force is amplified by the micro lever mechanism. The structure is symmetrical in the center, and the differential output method is used to detect the signal. The structure is optimized through simulation analysis and the overall structure design of the accelerometer is completed, so as to improve the sensitivity of the accelerometer and reduce the cross coupling. The modal analysis, sensitivity analysis, cross coupling analysis and harmonic response analysis of the accelerometer structure are carried out. The results show that within the range of ±20g, the x-direction scale factor is 423.6 Hz/g, the y-direction scale factor is 421.8 Hz/g, the x-direction cross sensitivity is 0.000 047%, and the y-direction cross sensitivity is 0.000 78%. The simulation results verify the feasibility of the designed structure.