The development of the Internet and the application of big data have made it possible to study the population migration between cities. Based on the analysis of the probability and direction of the intercity population migration in the three major urban agglomerations of China, this paper constructs the index of the population migration propensity according to the information searching behavior data of network users and predicts the probability of population migration by using Markov chain, so as to judge the future intercity population migration trend in urban agglomerations. The results show that Guangdong-Hong Kong-Macao Greater Bay Area and Yangtze River Delta Urban Agglomerations are still the active areas of population migration in China at present and in the future. The active degree of population migration tendency of Beijing-Tianjin-Hebei Urban Agglomeration is lower than that in Yangtze River Delta Region and Guangdong-Hong Kong-Macao Greater Bay Area, Although the physical distance between Beijing and surrounding cities is relatively close, the correlation degree of migration tendency is not high. In the future, the cities of Shanghai, Nanjing and Zhoushan in Yangtze River Delta Urban Agglomerations, Zhuhai, Hong Kong, Shenzhen, Guangzhou, Macao, Huizhou and Zhongshan in the Guangdong-Hong Kong-Macao Greater Bay Area, and Tianjin in the Beijing-Tianjin-Hebei Urban Agglomeration will be the main destinations of China’s population migration.
