新时代下，随着城市化进程的加快和新产业、新工艺的不断涌现，城市运行系统变得日益复杂，城市人员密集场所的数量和规模不断扩大，人们享受城市人员密集场所进行文化娱乐带来休闲、乐趣的同时，其带来的风险与威胁也越来越多。因此，识别并提取城市人员密集场所风险因素，并对城市人员密集场所进行风险评价，对于提高城市人员密集场所安全性具有重要现实意义。

以城市人员密集场所风险为研究对象，分析风险评价中存在的复杂因素相互影响及量化过程中主观性强等问题。首先，界定了城市人员密集场所概念，对城市人员密集场所事故致因及其风险演化特点进行分析。依据风险识别原则，对近些年的城市人员密集场所发生的事故案例进行统计分析，采用扎根理论对城市人员密集场所事故风险因素进行提取和分类，从人、物、环、管4个方面提取得到风险因素共16个，为后续的研究奠定重要的支撑。其次，运用序关系法（G1）和熵权法（EW）提出了改进的组合赋权法确定指标的综合权重进行量化分析风险，运用集对分析法（SPA）评价和预测城市人员密集场所的风险水平，并结合西安市D旅游景区进行实例分析，发现旅游景区的风险“较低”，总体的风险水平在向着安全的方向发展。最后，应用系统动力学对风险进行干预仿真研究，对风险因素的关联特征、路径特征分析，构建城市人员密集场所风险系统SD模型，表明组合干预对降低城市人员密集场所的风险具有明显的效果，其中提升安全建设保障在城市人员密集场所风险中有着至关重要的作用。

通过应用改进的组合赋权法，较好的处理了在城市人员密集场所风险评价中存在的风险不确定问题，具有较强的操作性和实用性，应用系统动力学进行风险干预仿真研究，为城市人员密集场所风险有效预警及管控提供有力的参考依据。

In the new era, with the accelerated urbanization process and the emergence of new industries and technologies, the urban operation system has become increasingly complex, and the number and scale of urban crowded places are constantly expanding. Therefore, it is of great practical significance to identify and extract risk factors from urban crowded places, and to conduct risk assessment of urban crowded places in order to improve the safety of urban crowded places.

In this paper, we take the risk of urban crowded places as the research object and analyze the problems of complex factors interacting with each other and the strong subjectivity in the quantification process in risk evaluation. First, the concept of urban crowded places is defined, and the causes of accidents in urban crowded places and their risk evolution characteristics are analysed. Based on the principles of risk identification, statistical analysis of accidents in urban crowded places in recent years is carried out, and risk factors in urban crowded places are extracted and classified using the root theory. 16 risk factors are extracted from four aspects: human, physical, environmental and management, which provide important support for the subsequent study. Secondly, an improved combination weighting method was proposed to determine the comprehensive weights of indicators using the sequential relationship method (G1) and the entropy weighting method (EW) to quantify and analyze the risks, and the set-pair analysis method (SPA) was applied to evaluate and predict the risk levels of urban crowded places, and the overall risk level is moving towards safety. Finally, applying system dynamics to the intervention simulation study of risk, the association characteristics and path characteristics of risk factors are analyzed, and a system SD model of urban crowded place risk is constructed, showing that the combination intervention has a significant effect on reducing the risk of urban crowded places, in which the enhancement of safety construction guarantee has a crucial role in the risk of urban crowded places.

By applying the improved combination assignment method, the risk uncertainty problem in the risk evaluation of urban crowded places is better dealt with, with strong operability and practicality, and the application of system dynamics for risk intervention simulation research provides a strong reference basis for effective early warning and control of urban crowded places risk.