Permanent magnet synchronous motor (PMSM) servo systems have become a core driving component in high-end equipment and automation due to their high power density, high efficiency, and excellent control performance. As applications such as computer numerical control (CNC) machine tools and industrial robots advance toward higher speeds, precision, and dynamic response, more stringent requirements are imposed on position servo systems in terms of tracking accuracy, response speed, and disturbance rejection capability. The "position + current" single-stage proportional-integral-derivative (PID) position servo control structure is favored for its fast position response; however, its design complexity, combined with disturbances such as parameter uncertainties and unmodeled dynamics, limits its application in high-end servo domains. To address these challenges, this article proposes a single-stage position servo control strategy based on adaptive backstepping. First, an adaptive backstepping design is conducted for the position servo loop to derive a virtual velocity reference. An adaptive observer is then designed to compensate for parameter uncertainties and unmodeled disturbances, and the q-axis current reference for torque control is derived through the virtual velocity closed loop, achieving integrated position-velocity control. A complete position closed-loop model is subsequently constructed to accurately analyze stability. Finally, simulation and experimental comparisons with the PID-based single-stage position control demonstrate that the proposed strategy achieves smaller steady-state and dynamic position errors, as well as stronger robustness against parameter uncertainties and unmodeled disturbances, providing an effective solution for high-performance high-end servo systems.