This paper focuses on the study of a bi-directional relief valve for vehicle shock absorbers. The performance of the solenoid valve significantly influences the overall efficiency of the vehicle damping system. In order to optimize its dynamic performance and ensure a better driving experience, an accurate dynamic model was developed to study the characteristics by numerical simulation approach. The model was validated by experimental results. With the validated model, the dynamic response of valve system under different operating conditions were discussed and selected some key parameters that have a significant impact on the dynamic characteristics by the Sobol sensitivity analysis method. Then, based on genetic algorithm, these parameters were optimized and the final optimization values were determined. Finally, the optimization was validated by comparing the experimental results before and after optimization. Under recovery stroke conditions, the maximum adjustment pressure increases 36.6 % and response time decreases 45 % compared to pre-optimization. This study proposes a more accurate modelling method and effectively improves the performance of the valve, which provides a validated methodology for enhancing the dynamic characteristics of electro-hydraulic control components in automotive suspension systems.