The Hartree-Fock-Bogoliubov (HFB) theory has recently attracted considerable attention in quantum chemistry as a novel strategy to account for the static electron correlation, which plays an essential role when breaking chemical bonds and treating diradical systems. The linear-scaling divide-and-conquer (DC) method is applied to the HFB method to treat large-scale bond-breaking and/or diradical systems with reasonable computational effort.