It is a new choice to use ∑-Δ ADC, based oversampling principle ,as analogdigital conversion unit to meet the needs of more accurate signals detection of MEMS gyro meter. A secondorder bandpass continuoustime ∑-Δ ADC which consisted of a secondorder bandpass continuoustime ∑-Δ modulator and a digital decimation filter was designed. The digital decimation filter was realized by twostage decimation filters, the first stage was CIC filter, the second stage was FIR compensation filter. The design of ∑-Δ ADC was proved effective to detect the simplified signals of MEMS gyro meter, about 104 dB SNQR was achieved by Matlab/Simulink modeling, and about 87 dB SNQR was achieved by circuits experiments.