For designing silicon micro-gyroscopes and optimizing their structures, the effects of intrinsic frequency and modal of a silicon micro-gyroscope on its performance were researched. On the basis of energy theorem, a theoretical formula of the intrinsic frequency was established, and the lowest frequency mode of the dual-mass vibrating silicon micro-gyroscope was analyzed. Then the analytical results were validated by the Finite Element Method (FEM) simulation and the experiment. Analysis results show that the largest analytical errors with respect to simulation and experiment are 8.6% and 10.6%, respectively. Moreover, the Allan Variance analysis was used to conduct a static performance experiment, and the results demonstrate that the Angle Random Walk (ARW) is 0.057 8(°)/hr12 and the measured bias instability is 0.459(°)/hr. As compared with the traditional modal ordering method depending on the FEM, the proposed theoretical model avoids complex structure parameter adjustment processing, complements modal ordering of the silicon micro-gyroscope and can be used in the structure optimization of the silicon micro-gyroscope.