With the frequent occurrence of various disasters and accidents, realizing the periodic assessment and visualization of urban safety and security considering multiple hazards is of great significance for safe urban development. In this paper, a periodic assessment system is developed for urban safety and security considering multiple hazards, based on WebGIS. This system consists of an assessment module, a visualization module, and an assistant module that integrates the assessment model to process the assessment data quickly and realizes the visualization of a thematic map and data statistics for rationalizing assessment results. The assessment of a typical urban area was carried out to prove that the created system can effectively conduct periodic assessments and support single-hazard and multi-hazard analysis and auxiliary decision-making. This system can be applied to the grid management and periodic assessment of urban areas at different levels, with high expansibility and application value. It can also help to promote the sustainable construction of a safe and smart city. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.