The invention relates to the technical field of power station water supply, and concretely relates to a power station boiler make-up water system mixed bed regeneration method. The mixed bed regeneration method comprises the following steps: 1)backwashing and layering; 2)standing; 3)pre-injecting soda acid; 4) feeding acid or alkali; 5) replacing cathode and anode; 6)performing front washing on anion resin, 7)washing in series; 8) discharging water; 9)mixing resins; 10)rapidly settling; 11)filling with water; and 12)performing front washing, opening a front washing intake gate, a front exhaust gate and a self-use salt removal pump. The mixed bed regenerating method has the beneficial effects that the step of water discharging is cancelled; the step of water discharging is changed to regeneration with a full filling method, after steps of feeding acid or alkali and replacing cathode and anode, the step of performing front washing on anion resin is added for ensuring the regeneration effect; the step of rapidly settling is added after the step of mixing resins, so that re-separation of the mixing resins can be avoided. The method employs new regeneration process, once mixing bed enables successful regeneration, and automatic regeneration can be realized.