Abstract: In order to judge the passing capacity of the pipe elbow and realize the measurement of the elbow parameters of the buried pipeline, the inertial navigation technology is used to calculate the parameters of the pipe elbow. The angle of pipe elbow is calculated by gyroscope data, and curvature radius and curvature are calculated with odometer data; the attitude at the beginning of the elbow is calculated by using the accelerometer data, and the direction of the pipe elbow is extracted by updating the attitude matrix. By performing the pipe section experiment with standard elbow, the results show that the method can accurately give the direction of the pipe elbow, and the comprehensive error of pipe elbow angle calculation is within 7%, which can meet the needs of engineering practice and has engineering practical value.