[PROBLEMS] To provide a central system for a dialysis treatment, whereby the usage of a disinfectant solution can be reduced while sufficiently disinfecting purified water and dialysis fluid channels, and a disinfection method thereof. [MEANS FOR SOLVING PROBLEMS] A central system for a dialysis treatment having a dialysis fluid-supplying unit (2) by which a dialysis fluid having a definite concentration can be prepared by using purified water, dialysis monitors (4) for supplying the dialysis fluid prepared in the dialysis fluid-supplying unit (2) respectively to blood purifiers (K), a fluid-feeding means (3) by which the dialysis fluid prepared in the dialysis fluid-supplying unit (2) is fed to the individual dialysis monitors (4), and a disinfectant solution-supplying unit (L2, P1) by which citric acid is supplied to a dialysis fluid channel in the dialysis fluid-supplying unit (2) so that a hot aqueous citric acid solution can be prepared, wherein a first circulatory path, which involves channels for flowing the purified water and the dialysis fluid in the dialysis fluid-supplying unit (2) and in which the disinfectant solution can be circulated, and a second circulatory path, which involves a dialysis fluid channel of the fluid-feeding means (3) and in which the disinfectant solution introduced from the dialysis fluid-supplying unit (2) can be circulated, are provided.
