The full-face hard rock tunnel boring machine ( TBM ) needs to adjust the pose of the cutterhead and the fuselage according to the position of the coal seam during the tunneling process of the coal mine gas extraction roadway, so that a certain safe distance can be maintained between the TBM and the coal seam. At present, the steering of the TBM in the tunnel rock roadway still needs to rely on the driver to artificially control the rotation angle. Due to the instability and non-real-time nature of manual operation, over-excavation and under-excavation of the tunnel rock roadway often lead to TBM jamming. Therefore, it is an inevitable trend of TBM intelligence in the future to adopt a real-time, stable and reliable control method to replace or assist the manual control of TBM pose. In this paper, a TBM pose control method is proposed for the turning and pose control of small diameter ( diameter less than 6m ) TBM in coal mine gas extraction roadway. The co-simulation model of TBM propulsion system is built by AMESim simulation platform and ADAMS dynamics software. Combined with the design axis of parametric characterization of extraction roadway, the master-slave control method is used for the propulsion system, and the PID controller is designed for the overturning angle and yaw angle of cutterhead to realize the real-time control of cutterhead pose. The effectiveness of the pose control method is verified by simulation analysis, which can be well applied to the turning pose control problem of small diameter TBM in coal mine gas extraction roadway.