With the accelerating process of globalization,cultural exchanges are increasingly frequent and the forms are increasingly diversified.As the carrier of cultural communication,film has become one of the important forms of cultural exchange.Chang An presents more than 40 Tang poetry,and the English translation of the subtitles is of great significance to the dissemination of Chinese culture.This paper takes Eugene Nida's functional equivalence theory as the theoretical basis,analyzing the translation of Tang poetry in Chang An.