In this paper, the calibration method of electrode gap of capacitive micro-electro-mechanical systems (MEMS) gyroscope with butterfly structure is investigated. An electrical calibration method based on resonance measurement is proposed, a high-precision weak capacitance detection circuit based on modulation and demodulation technology is designed, and the measurement and calibration of electrode gaps of different interface capacitances of the butterfly gyroscope are realized by switch control. The theoretical analysis model of electrode gap is established based on the working principle of gyroscope, the relationship between capacitance gap and output voltage is deduced, the platform for electrode gap measurement and calibration is constructed, and the gaps of different electrodes of several gyroscopes are measured and compared with the test results using CV analyzer and step profile. Compared with the CV analyzer test method, this method can effectively avoid the influence of parasitic capacitance, and the effective electrode gap can be accurately measured when the parasitic capacitance is unknown, and at the same time has a higher resolution. Compared with the step profile test method, this method can accurately reflect the gap size at the actual electrode position. The theoretical design value of the electrode gap of the gyroscope under test is 2.0 μm, and the distribution of the test values using the proposed method ranges from 1.92 to 2.2 μm, and the average test result using the CV analyzer is 2.004 μm (with known parasitic capacitance), while the average test value using the step profile is 2.11 μm.