Fire service agencies operate in high-risk disaster environments where operational safety is influenced not only by the severity of hazards but also by the internal social vulnerability of the organization. However, previous studies have primarily focused on the construction of indicators, while empirical validation of the causal relationships among these dimensions remains limited. This study employs Structural Equation Modeling (SEM) to examine the causal relationships between the dimensions of social vulnerability in fire service agencies and disaster-scene management mechanisms. A questionnaire survey was conducted among fire service personnel across municipalities in Taiwan, yielding 841 valid responses. Confirmatory factor analysis and structural model analysis were performed using SPSS and AMOS. The research framework comprises five dimensions: Duty Planning Management, Competency Management, Command and Control Management, Resource and Information Management, and Equipment Selection and Procedural Management. The results indicate that the proposed model demonstrates a good model fit and shows strong explanatory power for Resource and Information Management (R² = 0.928). Empirical findings reveal that Duty Planning Management significantly enhances Competency Management, which further strengthens Command and Control Management. In turn, Command and Control Management has significant positive effects on both Resource and Information Management and Equipment Selection and Procedural Management. The findings suggest that effective duty planning and a well-established command-and-control system are critical factors in improving disaster-scene safety management.