Paper Keywords: Speech Act Theory, Cultural Differences and Pragmatic Failure Abstract: Speech Act Theory is an important topic in pragmatics. In communication, people always try to achieve some implication by implementing some kind of agent behavior. However, due to cultural differences, the implication expressed by one party through agent behavior is often misunderstood by the other party, which leads to pragmatic failure and even communication failure. Speech act theory is an important topic in pragmatics. Austin explored the essence of human language activities through the analysis of daily language, thus laying a solid foundation for the formation and development of pragmatics. In cross-cultural communication, due to cultural differences, it often happens that the speaker can't correctly understand the other party's intention. This paper attempts to analyze this pragmatic phenomenon according to speech act theory and reveal the reasons of cross-cultural pragmatic failure. 1 Overview of Speech Act Theory Speech Act Theory was put forward by Austin J.L. Austin, a professor of philosophy at Oxford University in England. His book "How to Do Things with Words" published in 1962 is regarded as the foundation work of this theory. In his view, speaking is doing things. Words in human communication are not only sentences or other expressions used to describe and state things, but actually speech acts like "promise", "command" and "request". Language itself contains the power of action, that is, the power of speech act, which is called language power for short. According to different linguistic forces, Austin abstracted three acts from a complete speech act theory: 1 speech act illocutionary act. Its linguistic force lies in the proposition itself, and the speaker can say meaningful and signified sentences, and its main function is to state. Implication refers to giving meaningful words speech act force in a specific context, and accomplishing certain intentions and purposes while expressing semantics. 3 perlocutionaryact refers to the effect of speech act or agency act on the listener, Liu Zhencong, Yang Lira 2006:25-26. On the basis of Austin's research, Searle, an American philosopher, put forward the concept of indirect speech act theory, aiming at the defects of indirect speech act theory: when the speaker doesn't want to use behavioral verbs directly for some reason or intention, he will use indirect speech means to realize a certain speech act. Words that express speech acts indirectly are indirect sentences. Ran Yongping, 2006: 19 1. Searle pointed out that to understand indirect speech act, we should first understand "literal intention", and then infer its indirect intention from "literal intention", that is, the illocutionary force of sentence expression. 2 Pragmatic failure culture under cultural differences is the sum of material products and spiritual products created by human society in historical practice. People with different cultural backgrounds have differences in social norms, value orientation and thinking habits. In the process of cross-cultural communication, the understanding and application of various speech acts are completely different, which will inevitably lead to many pragmatic failures. In view of the above analysis, from the perspective of speech act theory, we will investigate several typical types of pragmatic failures caused by cultural background differences in order to attract people's attention. 2. 1 Greeting people in China, the most commonly used greeting phrase is "Have you eaten?" "Come?" Or "Where are you going?" Waiting for the agent to express the meaning of "greetings, greetings". However, if we directly translate this sentence into English and use it to greet native English speakers, they will be very surprised and even cause some confusion or disgust, because according to their understanding, "Have you eaten? The implication of "you want to invite him to dinner" and "so, you are here". "You have to tell him something, but" Where are you going? If you want to inquire about his privacy, communication is likely to be awkward. 2.2 Farewell in different cultural backgrounds, farewell also faces similar embarrassment. In China, besides saying goodbye, people often tell their guests to "take your time and come again next time". This kind of agency behavior is used to express the meaning of consideration and concern, in order to achieve the implication of enhancing friendly relations between the two sides. However, if we really say "go slow and be diligent" to an English-speaking friend, the other person's direct feeling will be more about accepting orders, and the speaker's original agency behavior will be completely misunderstood by the listener, and the effective behavior will turn into confusion or anger towards the other person. 2.3 China people are invited to visit us lively and often take the initiative to visit without being invited by others. On the other hand, British and American people often send a formal invitation to each other first, indicating the clear time, place and content, and asking the other party to give a clear answer. If not, when shaking hands and saying goodbye, you can say the last sentence: "I hope you can come to see me sometime, or we can have dinner together", and so on. This is probably a polite remark, and the listener will not necessarily meet the speaker in the future, and the speaker will not necessarily invite the listener to dinner. Wolff recorded hundreds of examples of American "invitations" and found that only one-third of the invitations were real invitations, and the rest were just pleasantries without specific time, place and content arrangement. Ran Yongping: 2006:344. However, if we don't understand the situation, interpreting these cliches as "real invitations" will inevitably lead to unpleasant consequences. China people are also very hospitable. At the dinner table, we often "advise guests to drink", "advise guests to eat", "do it" and "eat quickly" are words we often hear at the dinner table. It was originally an act of goodwill by China people, trying to make guests eat well. However, if translated directly into English, "e on, drink up" and "eatquickly" are similar to the orders of forcing people to drink and eat, which will lead to embarrassment and anxiety of guests. Because the original meaning can't be understood correctly, the expected meaning can't be realized naturally. 3 Conclusion To sum up, due to cultural diversity, the speech society in the world is naturally complex, far from "pure unity". People often have different understandings of the same speech act, which will inevitably lead to different illocutionary acts. In cross-cultural communication, if we are used to using our own cultural standards to measure and explain other people's speech acts in other cultures, it will certainly lead to unnecessary misunderstandings and conflicts.