Abstract: In view of problems of high cost of high-precision inertial navigation of underground vehicle and large drift of low-cost MEMS inertial sensor, an underground multi-sensor integrated navigation system was proposed, which uses bluetooth ranging information, MEMS inertial sensor and vehicle odometer information for integrated navigation. The system uses Kalman filter technology to fuse multi-sensor data, combines Bluetooth ranging information to suppress MEMS inertial sensor drift, and improve positioning accuracy of inertial sensor in a period of time; Vehicle position is predicted by MEMS inertial sensor to effectively filter out Bluetooth signal of interference tags, so as to improves data reliability; Integration of odometer data can make the positioning result more stable and reliable. The test results show that the positioning error of every 10 m is less than 3.2 m under the condition that the underground Bluetooth tags are distributed 10 m apart, which can meet requirements of underground navigation.