Urban residents' waste sorting plays a pivotal role in addressing the pressing challenge of the “waste siege” in China and is also closely associated with the quality of urban governance. We draw on the Technology–Organization–Environment framework to identify six key variables affecting municipal waste sorting in China: digital technology innovation, attention allocation, publicity and education, enforcement intensity, economic development level, and volunteer resources. Using the fuzzy set Qualitative Comparative Analysis (fsQCA) method to analyze the effect of conditions on municipal waste sorting, the results show the following: 1) A single condition is insufficient to ensure high levels of municipal waste sorting. We propose that the “multiple concurrency” of technological, organizational, and environmental conditions creates diverse paths for promoting municipal waste sorting. 2) We then identify three paths for waste-sorting promotion, which all require technological, organizational, and environmental conditions. In addition, the two paths obtained for low levels of municipal waste sorting are not the opposite of those obtained for high levels. By observing the above five paths of waste sorting, we deduced that digital technology innovation is indispensable in driving waste sorting, and 3) Our cross-case comparisons show that there are effective paths to waste-sorting governance that work for cities regardless of their location or piloting. In some cases, high levels of attention allocation and high levels of publicity and education are substitutes for each other. We recommend that local governments refer to their own unique characteristics and resource endowments when tailoring waste-sorting strategies.