In order to detect the rolling、pitch and yaw angle of high-speed-spin vehicle, a novel attitude sensor system is designed by using a digital signal processor TMS320F2812. The configuration of the sensor consists of two MEMS sensing elements and signal processing circuit and micro-processor. A new silicon MEMS gyroscope based on the Coriolis effect can sense three angular rate of spin vehicle, which can provide a synthesis signal, including roll, yaw and pitch angular rate. And a MEMS accelerometer reacts on demodulating the three angular rates. The design of the hardware circuit, the algorithm and implement of software are presented. The demodulation algorithm is validated by simulation experiment on the ground and the experimental results are presented.