Abstract: In recent years, sodium-ion batteries have attracted much attention due to their low cost, high safety, and excellent low-temperature performance. Among the candidate electrode materials, Prussian blue-based cathode materials show great potential for application due to their high energy density. However, there is currently no universally established technology for the recovery of valuable resources and the zero-discharge treatment of wastewater from the production of these materials. Addressing the limitations of traditional technologies, this study proposes a novel process characterized by "targeted precipitation–multi-membrane synergy–directional recycling" to enable resource recovery and zero-discharge wastewater treatment. The system involves two metathesis reactions and a two-stage membrane filtration process. In the first metathesis reaction, calcium chloride is used as a precipitating agent to react with sodium sulfate and sodium citrate in the wastewater. The optimal dosage of calcium chloride was determined to be 21 mg/mL through parametric optimization experiments. After solid-liquid separation, a filtrate containing sodium ferrocyanide and a mixed filter residue composed of calcium sulfate and calcium citrate were obtained. In the second metathesis reaction, sodium carbonate was used as a conversion agent for the mixed filter residue. The optimal conditions were determined to be: a sodium carbonate to calcium citrate ratio of 3:1, a 25% sodium carbonate solution, pH 10.5, a reaction temperature of 75 ℃, and a reaction time of 30–40 min. The filtrate then undergoes two-stage membrane filtration, during which ferrocyanide and chloride ions are effectively retained. Specifically, sodium ferrocyanide is recycled as a raw material for Prussian blue cathode production, while the remaining solution is treated by reverse osmosis to separate salts, and the resulting purified water is reused. Concurrently, the filter residue containing calcium sulfate and calcium citrate is repeatedly washed and separated to yield a residue mainly composed of calcium sulfate and calcium carbonate. Finally, the filtrate is evaporated and crystallized to yield a white powder mainly composed of sodium citrate. The recovery rate of sodium citrate exceeds over 99.6%, and sodium ferrocyanide can be directly reused in the production process under the optimized conditions. This work provides essential data and methodological guidance for resource recovery and zero-discharge wastewater treatment in the production of Prussian blue cathode materials for sodium-ion batteries.