Abstract: At present, the hole-opening orientation method can't satisfy the users' actual needs, the manual measuring is inaccurate and the hole-opening orientation instrument based on the three axis optical fiber gyro is too expensive in underground coal mine. In order to solve the above problems, a new type instrument for hole-opening orientation is designed. The paper introduced the overall scheme and working principle of the system. The author set up a hardware platform based on MSG7100D-300 gyroscope and KXR94 accelerometer with STM32 microcontroller as the CPU. The system adopts the static four-position method for north seeking and Kalman filtering tracking algorithm which could realize system measurement effectively and quickly. The correctness of the scheme is verified by the prototype test. The test results show that the north seeking time, the north finding precision and dynamic measuring precision of the hole orientation instrument based on MEMS gyroscope all meet the requirements of the drilling machine's opening orientation and the actual needs of the users.