In order to realize the intelligent mining of the fully mechanized excavation face, in response to the need for real-time accurate measurement of the roadheader's position and attitude at work, a combined measurement method for the roadheader's position and attitude based on strapdown inertial navigation and cylinder displacement is proposed. The method uses strapdown inertial navigation to measure the attitude information of the roadheader in real time, combines the displacement data of the cylinder moving the roadheader forward with the attitude information of the roadheader to calculate dead-reckoning, and uses the standard Kalman filter algorithm to combine the strapdown inertial navigation data and the cylinder data Perform fusion to suppress the divergence of inertial navigation measurement results and improve the accuracy of pose measurement. The results of downhole experiments show that the pitch angle, roll angle and heading angle measured by the combination of inertial navigation and the cylinder are0.018596 deg ,0.004635 deg,0.011898 deg and when the intelligent tunneling robot is stationary for 1 hour; In the process, the position error calculated by the combined measurement system is less than 3.5cm and 2cm in the x-axis and y-axis directions, respectively, which overcomes the problem of cumulative errors caused by the pure inertial navigation solution.