Abstract: In order to address the practical issue of unstable tunnel axis quality caused by manual control of the shield machine, the motion mechanism of the shield machine under the dual vector effects of load and thrust is analyzed.A method for autonomous control of the shield machine's posture based on thrust vector technology is proposed, and schemes for autonomous planning of shield motion path and intelligent control of thrust vector are presented. This method is applied to large-diameter shield tunnelling. The practice demonstrates that the target thrust of the shield machine maintains a fixed deviation from the actual value, and the shield machine's excavation speed remains stable. The effective execution of the target thrust torque enables accurate steering control in both the horizontal and elevation directions, and the shield machine's actual posture gradually approaches the set target.