In order to explore the potential of residual fatigue life of damage-containing structures to meet the requirements of high reliability, the residual fatigue life test of damage-containing structures made of alloy steel material 30CrMnSiNi2A is carried out, and the residual fatigue life dispersion and its influencing factors are analyzed.The test procedures are simplified according to the results of fatigue comparison test between test pieces containing pre-cracked damage and pre-set wire-cut damage under equal amplitude spectral loading.The qualitative analysis of remaining fatigue life of damage-containing structures is performed under different heat treatment processes and different load levels. The test data show that the heat treatment process is able to improve the strength limit of alloy steel materials, reduce the load level, and effectively improve the remaining fatigue life of damage-containing structures. Under the conditions of different treatment processes and different load levels, with the increment of damage in size, the difference in the scattering factor of the remaining fatigue life increases. The damage being larger in size, the residual fatigue life of the heat-treated damage-containing structure test pieces under a low load level is lower, and the life dispersion is lower. By doing so, the remaining fatigue safety life can be effectively improved to meet the reliability requirements.