Aiming at the structural safety of large-tonnage steel cables in nuclear power plant containment, three-dimensional finite element method is used to establish a fine analysis and calculation model considering the influence of anchorage, grid reinforcement and channels, and the distribution of principal stress and transfer mechanism of concrete in anchoring area are studied. Combined with the local pressure stress distribution law of concrete in anchoring area, theoretical basis is provided for optimizing anchorage structure and reducing cost. The results show that using mesh reinforcement instead of spiral reinforcement can improve the cracking bearing capacity of specimens and effectively control the development of splitting cracks. The stress of the anchor itself is lower than the yield stress of the material during tensioning. The tensile fracture of the lower side of the anchor plate is the main type of damage that may lead to the damage of the special anchorage of the nuclear power plant containment in the process of cable tension.