With the rapid economic development and frequent cultural exchanges

a large number of excellent English films have been introduced to China. In this circumstance

the film industry has been gradually developed and the demand of subtitle translation has been increased. In order to achieve cross-cultural communication through subtitle translation

translator should not only accurately express superficial meaning of subtitle but also vividly convey profound meaning such as various emotions

personalities and images of characters. It is easy to find that subtitle is primarily composed of conversations. Therefore

translator should take advantage of speech theory as guidance in the process of subtitle translation. Proposed by J.L. Austin

speech act theory has an important guiding role in subtitle translation. As a core theory of pragmatic

speech act theory mainly focuses on locutionary act

illocutionary act and perlocutionary act. This paper analyzes subtitle translation from the aspect of locutionary act and illocutionary act.Being released in 2018

the film called Green Book enjoys great popularity. Due to its fascinating story and profound connotation

it won Best Picture at the 91st Academy Awards. Under the guidance of speech act theory

this paper discusses subtitle translation of the Green Book and selects conversations from the film as cases. The author hopes that this paper will provide some suggestions for further study of subt