Artificial Intelligence (AI) mainly means to utilize electronic and mechanical devices to substitute and imitate some human intelligence. With the development of science and technology, the application of AI in computer games is increasingly wide, which greatly encourages the development of computer games. This paper studies the application of AI in computer games. The author classifies AI technology on the basis of its functional distinction, performance distinction and behavior distinction in computer games and illustrates its function and operating principle in computer games. Moreover, the author enumerates the major AI technologies used in computer games and makes a brief discussion about their functions and advantages and disadvantages in games. In addition, the author analyzes the design principle of AI system in computer games. Then based on work experience and related research results, the development trend of AI technology in computer games is discussed.