Modern film, television and theater works not only reflect the social reality, but also inherit and promote the traditional culture, and at the same time, absorb the world's outstanding culture. The article introduces the basic elements of the cultural identity of modern film and theater works, and analyzes them in depth from the aspects of value and function, so as to build a theoretical bridge for the following specific research. In addition, this article discusses the method of constructing and expressing cultural identity in film, television and theater works, using literature research method, text analysis method and empirical analysis method to carry out the research on the construction and expression of cultural identity in modern film, television and theater works. Modern film and television drama works have a higher sense of cultural identity construction and expression of identity, and the ratings are 0.182~0.578 percentage points higher than traditional film and television works. Cluster analysis verifies the reasonableness of the system of drama cultural identity construction and expression effect constructed in this paper, and with 10 locations extracted, the comprehensive drama cultural identity construction and expression effect is 0.782, which is a good performance. The symbols of dress culture (4.70) and behavior culture (4.33) in the work of Taeming Fenghua have gained a high degree of recognition from the audience, and have constructed and expressed theatrical cultural identities at different levels.