针对双向电容-电感-电感-电容（CLLC）谐振变换器传统设计方法中仅对满载效率作定性分析、谐振频率选取过度依赖经验的问题，本文提出了一种基于效率模型的参数优化设计方法。首先，通过基波近似法分析变换器工作特性，建立了峰值增益、增益线性及零电压开通（ZVS）约束条件关于参数K，Q的约束解析式；继而，通过时域分析，在不同负载下综合考虑开关损耗与磁性元件损耗，通过参数K，Q，R_o构建了精确的变换器效率模型。随后，在设计约束可行域内通过效率模型实现了在一定频段内的变换器最优设计。仿真与实验测试结果表明，所提设计方法可在满足变换器电压转换需求、实现器件软开关的同时，兼顾高效率与高功率密度。

Addressing the limitations of traditional bidirectional CLLC resonant converter design methods—which only perform qualitative analysis of full-load efficiency and overly rely on empirical resonance frequency selection—this paper proposes a parameter optimization design approach based on an efficiency model. First, the converter's operating characteristics are analyzed using fundamental frequency approximation, establishing analytical constraints for peak gain, gain linearity, and Zero Voltage Switching(ZVS ) with respect to parameters K and Q. Subsequently, through time-domain analysis, an accurate efficiency model is constructed using parameters K, Q, and R_o, comprehensively accounting for switching losses and magnetic component losses under various loads. Subsequently, within the feasible design constraints, the efficiency model enables optimal converter design across a specific frequency band. Simulation and experimental results demonstrate that the proposed method achieves high efficiency and power density while satisfying voltage conversion requirements and enabling soft switching of components.