In order to solve the problem that the snake shaped pipeline detection robot is difficult to locate because it is in the underground pipeline, a high-precision strapdown inertial navigation system (SINS) is designed for the snake shaped pipeline detection robot based on Newton's second law. The system is equipped with nine axis inertial measurement unit (IMU) to measure the acceleration and angular rate information of snake robot, integrate Kalman filter algorithm to compensate the error of positioning system, construct strapdown inertial navigation system attitude matrix by quaternion method, update the attitude, and then integrate to obtain velocity and displacement. The speed and displacement of the robot are analyzed and calculated by MATLAB software according to the above algorithm, and compared with the real speed and displacement of the robot to verify the reliability of the algorithm. The experimental results show that the maximum positioning error of the algorithm is no more than 4.7%, which can provide accurate speed and position information for the pipeline detection robot, and has high practical value and significance.