With the expansion of urbanization, the interaction between different hazards has become increasing evident. In order to promote sustainable development of urban areas, it is particularly important to systematically analyze and evaluate urban safety and security under the coupling effect of multi-hazard risks. In response to the practical needs of urban safety and security assessment practice, this paper constructs an application-oriented urban safety and security quantitative assessment methodology. First, following the comprehensive risk management perspective, the logical relationship between urban safety and security elements is analyzed. It proposes “comprehensive screening, key analysis, and comprehensive evaluation” as a new assessment concept. Second, a system of urban safety and security assessment methods consisting of a weighting method and a function model is constructed. The function model includes two sub-models: a quantitative risk assessment model that considers triggering effects and a quantitative assessment model of emergency capacity that considers the evolution of emergencies. Finally, the method was applied to a coastal urban area in south China. The case study proved that the proposed method system can not only effectively evaluate various disaster risks and emergency capacity but also provide evidence for the formulation and implementation of urban safety and security management measures. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.