Based on the data from 2011 to 2017, the non-equilibrium, convergence and causes of tourism development in the Yangtze River Delta are analyzed. It is found the problem of unbalanced development of international tourism in the Yangtze River Delta is outstanding, and domestic tourism tends to be balanced. Tourism development showed a general convergence of conditions, and tourism revenues showed category convergence. The tourism development of each city has the characteristics of spatial convergence, forming the spatial distribution pattern of “pyramid” in “Shanghai- traditional tourism-developed cities in Jiangsu and Zhejiang -other cities”. The improvement of the quality of tourism resources and the increase in the number of employees in the tertiary industry not only promoted the development of international tourism in the Yangtze River Delta, but also increased the probability that the Yangtze River Delta city will become a “convergence club with a high average level of international tourism development”. The expansion of opening up and the improvement of tourism traffic have played an overall role in promoting the development of tourism in the Yangtze River Delta. The improvement of the urban ecological environment and the help from the government's administrative forces has prompted cities to become members of the convergence club with a higher level of tourism development.