Theater performance has a long history and is an important form of expression in the development of art. The whole performance is mainly accomplished through the actors' lines, movements and feelings, etc., so that the audience can feel the ideas conveyed by the theater performance. Therefore, physical performance and emotional expression is an important part of theater performance, and the degree of its mastery by actors determines the effect of theater performance to a certain extent. This paper introduces and discusses the physical performance and emotional expression in theatrical performances, analyzes the way of expression of physical language in different emotional scenes, including joy, anger, sadness, fear, tension and other emotions, and analyzes the application skills of physical language in emotional expression, and after further analysis and research, proposes a strategy for actors to promote the mutual promotion of physical performance and emotional expression in theatrical performances, which can help actors to master the content and essence of the performance, so that they can better master the content of theatrical performances. It can help actors to deeply grasp the content and essence of theater performance, so that they can better display their own style on stage and find their own inspiration.