In order to analyze the influence of cavity depth on runway safety，a numerical simulation was carried out using the finite difference method.A total of 208 sets of different working conditions were designed by taking into account factors such as different aircraft types，runway dimensions，and cavity depth and area.Based on the runway life model considering the exponential decay of the structural condition，an analytical method was proposed to evaluate the impact of the cavity on the runway life.The results show that the bending and stress of the runway increase gradually with the increase in the cavity depth，but the growth rate is getting slower and slower.There is a coupling effect between the impact of cavity depth and cavity area，and the impact of cavity depth starts to appear when the cavity area is larger.In the cloud diagram of the influence of runway bending and stress，there is a non-sensitive area. The proposed runway bending rate development index and stress development index can be used to evaluate the influence of the trend of the cavity，and with the increase in the cavity area and depth，the above indexes have a peak area.According to different loads，runway structures，and take-off and landing times，the influence diagrams of cavity degree and remaining service life are drawn，which can quickly evaluate and analyze the influence of the cavity，thus guaranteeing the structural safety of the airfield runway.