Nanning is one of the 46 key cities in China to establish a municipal solid waste classification system before the end of 2020, and the garbage classification work ranks in the top in many quarters. At the same time, it still faces some difficulties in the implementation of waste classification policy. Exploring people's understanding of domestic waste classification is of great significance to the improvement of waste classification policy and the implementation of waste classification work. Based on the data obtained from the field survey and questionnaire survey of Nanning residents, this paper obtains the residents' cognition of domestic waste classification policy, and obtains the influencing factors of residents' cognition of domestic waste classification policy through empirical analysis. The results show that the factors affecting residents' cognition are government regulation, publicity and education, incentive mechanism, public participation and supporting facilities, while individual wishes and behaviors, charging mechanism and community management have no significant impact on the domestic waste classification policy. According to the analysis results, this paper discusses the problems and reasons existing in the cognition of urban residents' domestic waste classification policy, and puts forward some suggestions for improvement and optimization. First, strengthen publicity and education to promote residents' cognition; The second is to strengthen government control and improve detailed policies and regulations; Third, pay attention to the supervision and implementation of reward and punishment measures, and promote the standardized implementation of classification behavior; The fourth is to build and improve the garbage classification and treatment system; Fifth, broaden the channels of public participation.