Urban quality represents the spiritual taste and development quality of a city, and is the unity of the two. The level of urban quality reflects the level of the whole process of a city's planning, construction and management, and also directly affects the convenience and comfort of citizens' life, as well as relates to the agglomeration and attraction of various resource elements such as talents and industries. In other words, it is a comprehensive reflection of a city's strength, directly reflecting a city's economic development strength, urban social and cultural conditions, the beauty of the ecological environment, the level of public services and the living conditions of residents. China's economic development has entered a new period, has shifted from the stage of high-speed growth to the stage of high-quality development, and a clear understanding of the quality of the city is of great significance to high-quality development. This paper uses principal component analysis to conduct a comprehensive evaluation study of urban quality in 16 cities and towns in Yunnan Province from five dimensions: quality of urban economic development, social and cultural quality, quality of ecological environment, quality of public services, and quality of life of residents, using empirical data for the period of 2017-2021 as a sample of 16 cities and towns in Yunnan Province. The study found that although the comprehensive index of urban quality of each state and city in Yunnan Province has been steadily increasing year by year, the gap between the states and cities has not been significantly reduced. The development level of city sub-quality in each state and city in Yunnan Province is not balanced, and there are geographical differences, with a few cities, such as Kunming, having higher quality, while the quality of the majority of cities needs to be improved. The comprehensive scores of these city qualities are affected by indicators of economic development, social progress and environmental protection, and also show their own characteristics and advantages. In order to improve the quality of cities in Yunnan Province, it is recommended that policy guidance be strengthened, coordinated development among cities be promoted, investment in environmental protection be increased, and the development of social programs be advanced.