The hydraulically controllable reciprocating seal (HCRS) is a novel intelligent sealing technology capable of online performance regulation, making it one of the preferred solutions for highly reliable seals in the industrial field. However, the impact of structural parameters on the performance of it remains unclear, complicating efforts to provide precise guidance for structural design. To address these issues, this paper first employs a mixed thermoelastohydrodynamic lubrication (TEHL) model to perform a parametric analysis of how structural parameters affect the static and dynamic performance of seals, identifying key influencing factors. Secondly, a multi-objective optimization model was established to derive the optimal structural design using a comprehensive balance method. Finally, the performance results before and after optimization were compared. The results indicate that the width of the slide ring, the air side angle of the slide ring, the inner diameter of the slide ring, and the length of the internal pressure cavity are critical factors influencing sealing performance. Following optimization, the maximum von Mises stress in the seal was reduced by 51.5%, net leakage decreased by 12.9%, and friction power loss reduced by 2.25%. This demonstrates that the optimization method is effective for designing seals with low leakage, low friction, and high reliability.