As a new national economic support belt and the most important east-west axis in national land development strategy in the age of “New normal”，improving the S&T innovation capability of Yangtze River Economic Belt and relative node cities is a key action to drive the regional industrial transformation and upgrading as well as to promote regional development. Based on the theory of city innovation system，this paper constructs the evaluation index system of S&T innovation capability of the core node cities along Yangtze River Economic Belt，which conclude 22 specific indexes about the major body，performance and environment of S&T capability. Then use AHP and entropy method to analyze and evaluate the S&T capability of 14 core node cities include Shanghai. The results show that the highest scientific and technology innovation ability cities are Shanghai，Nanjing and Suzhou；Hangzhou，Wuhan，Wuxi，Changsha，Chengdu，Hefei and Ningbo take second place；because of the low general condition and environment，the S&T innovation ability of Chongqing，Nanchang，Kunming and Guiyang are the lowest. Based on the assessment results，the paper analyzes some main problems existing in the development of S&T innovation in Yangtze River Economic Belt. After that，several suggestions are put forward on how to promote the regional S&T innovation cooperation in Yangtze River Economic Belt.