The accident rate in the Korean construction industry is rapidly increasing each year. In particular, the mortality rate from human accidents in construction is very high compared to that of other industries. This indicates that the safety activities carried out at the national level have not been effective in reducing the accident rate. To resolve these problems, the risk factors for human accidents should not only be forecasted in advance, but should also be controlled, monitored, and managed from the commencement to the completion of construction projects. However, most studies on this topic have only listed the importance of risks based on the frequency of safety accidents rather than providing a quantitative analysis. Therefore, it is necessary to develop a model that can analyze and quantify the pattern of human accident risks. The purpose of this study is to develop a quantification model for human accidents in South Korean construction sites. To this end, insurance claim payout data were collected and analyzed to develop a risk quantification model using a Monte Carlo simulation. The results will be used as base data to develop a construction site safety management checklist and human accident prediction model.