It is of great significance to study the emotional evolution characteristics of significant sports events, to understand and master the changing law of online public opinion topics, to increase the attention and influence of sports events, to promote the dissemination of sports culture, and to correctly guide the direction of online public opinion on sports events. By dividing the life cycle of "Hangzhou Asian Games" microblog topics, using the LDA topic model and SnowNLP sentiment analysis, we mined the topics of online public opinion, analyzed the characteristics of public sentiment, and portrayed the sentiment evolution of "Hangzhou Asian Games" microblog topics in three dimensions: time, space and gender. The results show that Sina Weibo users are mainly optimistic about the topic of "Hangzhou Asian Games." The economically developed provinces in the southern and eastern regions are more optimistic about the topic than the economically less developed provinces in the western and northeastern regions, with higher user participation. In each life cycle, the emotional focus and emotional tendency show positive emotion>neutral emotion>negative emotion, and there are differences in the public opinion attention and emotional state of different topics in different periods, regions, and genders. Compared with other public opinion events, the emotional change of sports events public opinion is distinctive and unique, and its emotional evolution process is closely related to the development of different themes at different phases of sports events.