This paper takes the response of the happiness level of urban residents in less-developed areas to tourism urbanization agglomeration as the research objective. It constructs a model to identify and measure the response intensity of the happiness level of urban residents to tourism urbanization agglomeration. The results show that: (1) The agglomeration of tourism urbanization is a one-way Granger causality of the happiness level of urban residents. (2) Due to the influence of tourism urbanization agglomeration level, the happiness level is affected by different external factors of happiness in different periods, and the grey correlation changes from spiritual cultural environment, natural ecological environment and other non-economic factors to social security environment, life quality environment and other economic factors. (3) The effect of tourism urbanization agglomeration on the happiness level of urban residents is different from the traditional path of improving the happiness level which meeting people's material needs first and then meeting their non-material needs. Instead, it passively improves the "non-material" needs and then drives the "material" needs to improve the happiness level. The research results can provide theoretical support and reference for similar underdeveloped regions to improve the happiness level of residents through the development of tourism urbanization.