Abstract In this paper, according to dimensional analysis, the dimensionless function of the intensity of the air shock wave overpressure of the explosion in structure leaking into a tunnel is established. Forty-eight experiments were carried out focusing on some influencing factors such as explosive charge, explosive depth, ratio of reinforcement, concrete matrix strength, and existence of the structure, revealing the influence laws of explosive charge, explosive height, ratio of reinforcement and concrete matrix strength on the overpressure intensity of air shock wave. Then, engineering calculation methods for leak shock wave effect are obtained, which include the overpressure distribution of shock wave in explosive tunnel in structure, equivalent coefficient of explosive charge compared with explosion in tunnel as well as the reduction factor of shock wave with or without structure.