Purpose <p>Beam position monitors (BPMs) play a critical role in fourth-generation synchrotron light sources. Tomaintain the stability of the charged particle beam and reduce beam energy loss, it is essential to achieve ultra-high position resolution while simultaneously minimizing beam-induced wakefield effects.</p> Methods <p>This study systematically investigates the influence of electrode geometries—particularly the inclination angles of frustum-shaped electrodes—on wakefi eld eff ects and measurement performance by combining theoretical analysis with electromagnetic simulations.</p> Results <p>Compared with conventional cylindrical electrodes, the optimized design can reduce the peak beam coupling impedance by more than 50% without compromising position-measurement accuracy. Further analysis confirms that optimizing the inclination angle of the BPM’s frustum-shaped electrodes can significantly reduce the electromagnetic energy coupled from the beam into the quasi-resonant cavity of the feedthrough, thereby effectively suppressing wakefield effects and energy loss while maintaining high resolution in position measurement.</p> Conclusion <p>Our investigation provides valuable guidance for the design of BPMs in future high brilliance accelerators.</p>