In this study，a surface acoustic wave（SAW）resonator，based on an X-cut LiNbO₃-on-Insulator（LNOI）substrate，is investigated. Pseudofinger length weighting techniques is used to suppress transverse modes while precisely maintaining the resonator’s quality factor（Q factor）. SAW resonators with different weighting electrodes are designed and fabricated. Then，the effects of weighting period and amplitude on the transverse modes are systematically investigated. A comparative analysis reveals the optimal weighted electrode configuration for the X-cut LNOI SAW resonator at a frequency of 2.5 GHz. Experimental results show that the weighted electrode effectively mitigates transverse modes induced by the X-cut LiNbO₃ material，thereby enhancing the overall performance of the SAW resonator.