This paper explores the music psychology behind the vocal performance of Lin Huiyin, the core character in China’s first Chamber opera “Farewell to Cambridge”, with a focus on analyzing Lin Huiyin’s aria “A Peach Blossom.” Lin Huiyin, portrayed by the renowned Chinese singer Lei Jia, serves as an entry point for an in-depth exploration of the psychological dimensions of opera music. Utilizing music psychology as the theoretical framework, this study interprets the emotional expression and psychological connotations behind the performance from the perspectives of musical characteristics such as melodic progression, rhythmic variation, and musical expression. The research reveals that musical features are closely related to character psychology and audience aesthetic experience. Music can accurately convey the inner world of characters and evoke emotional resonance in the audience. This study not only enriches the theoretical content of opera music psychology but also provides psychological references for opera performance practice, thereby enhancing the expressiveness and appeal of opera art.