Based on the analysis of the influence of core subjects on the carrying capacity of the tourism environment, this paper constructs the “PSR” mechanism and builds the urban tourism environmental carrying capacity index system from three perspectives of natural, economic and social components of the tourism environmental system. The article researches the tourism environmental carrying capacity from three perspectives: economic benefit, social benefit, and environmental benefit, and constructs the objective function from three perspectives: maximizing the average tourism economic income, minimizing the emission of pollutants, and maximizing the number of accommodated subjects. Taking the state of the tourism environmental carrying capacity index as the constraint, the multi-objective optimization model of tourism environmental carrying capacity is constructed, and the optimization model is simulated and solved with the help of NSGA-II to provide a reference for the choice of decision-makers scheme. According to the evaluation of the tourism environment carrying capacity by the formula, the tourism environment carrying capacity coefficient increased from 0.1118 in 2012 to 0.8434 in 2021. The natural tourism environment carrying capacity coefficient increased from 0.2686 to 0.7893, the economic tourism environment carrying capacity coefficient increased from 0.064 to 0.8183, and the social tourism environment carrying capacity coefficient increased from 0.0925 to 0.9248. The evaluation and optimization of tourism environment carrying capacity conducted in this paper are of practical research value for guiding the sustainable development of tourism destinations.