The paper is to analyze the potential hazard risk of tunnel operation caused by traffic accidents, especially dangerous goods transport accidents. Firstly, the risk of tunnel operation hazard is quantified by improving the personal risk acceptance criteria method. It is assumed that the tunnel has only one traffic accident at the same time, and the damage caused by the accident is divided into primary hazard and secondary hazard. The tunnel operation hazard calculation model is established to evaluate the risk of personal injury caused by different tracking vehicles. Then the results show that: (1) In the peak hours, the hazard risk of tunnel operation increases by 22. 05% in the case of dangerous goods transportation, which indicates that the mixed traffic flow in the tunnel greatly increases the insecurity of the tunnel operation. (2) The secondary hazard growth is particularly significant, so the secondary accidents of the tracking vehicles caused by the accidents of the dangerous goods transport vehicles are more serious. Finally, the relevant recommendations of the tunnel operation organization are proposed.