This article studies the impact of intervention measures with nudge characteristics on residents’ waste separation behaviours under the background of new ‘Beijing Municipal Regulation on Domestic Waste Management’. We analyse whether and how nudge interventions affect residents’ waste separation behaviours through the Ordered Logit model and mediation analysis. Our research results show that three nudge tools, namely, the timing and fixed-point separation system, the cleaning staff guidance system and the uniform clothing and styling, can effectively promote residents from low classification levels to high classification levels. In the process of nudging interventions, factors such as residents’ waste separation habit, external environmental perception and the sense of separation efficiency play a mediating role. Our study’s findings suggest that effective nudge tools are helpful in cultivating residents’ separation habits and hence we recommend that policy makers promote and popularise them in their attempt to improve domestic waste management behaviours.