In this research, the analysis of the technical views of experts and the management of construction projects in Tehran Municipality regarding the assessment of the risk of work accidents in the development, construction, and operation stages of construction projects, using the FMEA analytical approach in two fuzzy and non-fuzzy dimensions (CRISP) with twelve The index in the construction stage and six indicators in the operation stage were carefully evaluated and measured. Risks caused by the collapse of nearby buildings on workers, the collapse of buildings in demolition and reconstruction projects, which are mainly related to non-standard demolition operations, as well as the fall of people due to welding operations and falling from scaffolds, lifts, and cranes, as the most dangerous and most frequent occupational accidents in the industry. The buildings of this area were identified. Based on the analytical findings of this model, the average risk of occupational accidents in the construction industry reached 346 in the construction phase and 97 in the operation phase. The fuzzy equivalent values for risk prioritization in the construction and operation stages showed 355 and 129 numbers on average, respectively. Following the implementation of the correction suggestions, the risk values obtained for the construction phase in the non-fuzzy mode were reduced to 247 and in the fuzzy mode to 255. In contrast, the exploitation phase was reduced to 58 in the non-fuzzy mode and 84 in the fuzzy mode.