Many studies regarding construction safety management have been conducted. However, it is insufficient to research on external construction site. As a result, ordinary people around the construction site have injured and have a negative view when they think construction industrial since it has regarded having an overfull industrial accidents on media. To break the stereotype and prevention of accident on construction industry have been emphasized at this point in time, it is necessary to establish a comprehensive safety management system which is considered not only internal safety management but also external safety management. Therefore, the objective of this study is to develop the human accident risk quantification model by utilizing the third party payout data which occurred by incomplete safety management on external construction site. This study is conducted as a basic study for developing safety management manuals on internal·external construct site. In the future, it is expected to be used as a reference.