This chapter presents the concept of cloud–edge–device collaborative technologies and innovative applications for smart cities. Drawing on years of applied research and innovation across multiple smart city domains, Gloryview Technology has established an AIoT-based foundational technology system for smart cities. In response to emerging needs in smart city development, the chapter introduces a cloud–edge–device collaborative technology framework comprising “four core technology systems and one innovative application framework,” providing new technical support for the high-quality socioeconomic development of China’s urban agglomerations.