Since The Big Bang Theory was introduced to our country, it has been warmly welcomed. It is its unique contents, characters of distinctive personalities, and humorous dialogues that enable it to be one of the most popular sitcoms now. The success of The Big Bang Theory is not only because of its own artistic charm but also because of its skillful and accurate subtitle translation. Chinese audience can learn about social values of foreign countries and also improve their oral English through subtitle translation. Therefore, subtitle translation is especially important. The thesis takes the subtitle translation of The Big Bang Theory as the example to analyze how subtitle translation helps audience to understand and enjoy the humorous dialogues from the perspective of Functional Equivalence Theory. Based on exemplification, the thesis discusses the principles and procedures in the subtitle translation from the aspects of linguistic, stylistic, and cultural equivalence to help people to better understand the subtitle translation and promote Chinese-English cultural communication.