Waste source separation is an essential section of successful municipal solid waste management, and the city governments in China are shifting from building massive waste treatment facilities to regulating residents' waste separation behaviour (WSB). In order to promote residents' WSB, Beijing, the capital of China, implemented the new version of municipal household waste management regulation (NEMAR) and allocated more funds. This article constructs a theoretical framework to analyse the relationship between the NEMAR and residents' WSB from the perspective of policy tools, and uses propensity score matching method to evaluate the NEMAR's effectiveness on promoting residents' WSB, with first-hand data collected by distributing two rounds of questionnaires in Beijing. Results show that the NEMAR in Beijing have significantly improved the frequency and accuracy of residents' WSB. The command-control tools such as fines are effective to enhance WSB. The information guidance tools such as propaganda in community publicity column, banner and brochure could significantly promote residents' WSB frequency. Training seminars could enhance residents' WSB accuracy. The economic incentive tools are ineffective, and the policy of direct material rewards even hampers residents' WSB. This research reveals the effectiveness of the new policy and different tools in promoting residents' WSB. It could provide evidence for policymakers to utilize more effective governing tools and optimize the allocation of public resources.