With the development of globalization and cross-cultural communication, more and more artistic works are introduced into the promising market, China, including film and television works, music and novels. Of which, American TV series have become one of the hottest subjects, which arose enthusiastic pursuit and discussions among Chinese. Compared with domestic TV series, it contains more exciting plots and beautiful background music. What’s more, the quality subtitle is an essential part of this introduction. Regarding the theory put forward by Roman Jacobson, the founder of Prague school, translation is divided into three categories: intralingual translation, interlingual translation and intersemiotic translation, and subtitle translation is kind of interlingual translation. It means an interpretation of source language by means of target language. For film and television works, subtitle acts as a bridge between source language and audiences of target language as well as playing the role of communication and transformation of original emotions and image, which is the best illustration of functional equivalence theory developed by Eugene Nida. Differentiate from traditional literary translation, subtitle translation has its own unique features despite its being an emerging field. It has spatial and time constraint and must reproduce the content of source language as accurately and elegantly as possible within the limited time, as a result, this paper intends to carry out a further study on subtitle translation and functional equivalence theory. In 2018, the American TV series Killing Eve created a fad at home and abroad and the successful subtitle translation definitely contribute to it. In my perspective, its subtitle translation can be considered the great illustration of the principles and requirements of functional equivalence theory, which is a best case to study. From the perspective of functional equivalence theory, the paper has potential to produce a better understanding of subtitle translation's classification, features and related study at home and abroad. Give priority to the role of functional equivalence theory played in subtitle translation so as to give a boost to its development.