Today, tower cranes are widely used to lift materials in construction sites. Most of the construction workshops are very small and close to the city center. Therefore, the installation and dismantling of tower cranes in construction workshops is inevitable and at the same time dangerous, and not paying attention to it leads to the loss of workers' lives, as well as delays in construction plans or damage to buildings under construction. In the present study, critical risks were identified using the effect analysis method. Next, using the AHP method, other criteria affecting the safety of working with a tower crane were evaluated, and as a result, critical risks were prioritized using the TOPSIS method.

The results of the research showed that the experience of the operator is the most important factor in ensuring safety in construction sites, followed by the absence and unsoundness of safety indicators and equipment, defects in the foundation, column and rail of the crane, the lack or absence of protection during transportation and Transporting materials and not having an emergency stop button are prioritized. As presented, the proposed research model has the ability to identify and prioritize risks and can lead to the control of risks, reduction of accidents and ultimately increase productivity by helping to allocate limited organizational resources correctly.