In  recent  years,  sodium-ion  batteries  have  attracted  much  attention  due  to  their  low  cost, high  safety,  and  excellent  low-temperature  performance.  Among  these  materials,  Prussian  blue-based cathode materials show great potential for development due to their high energy density. However, there is  currently  no  applicable  technology  worldwide  for  recycling  valuable  resources  and  zero-discharge treatment of wastewater from the production of Prussian blue-based cathode materials. After confirming the poor performance 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 treatment of wastewater, involving 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 is determined to be 21 mg/mL through single-factor experiments. After solid-liquid separation, a filtrate containing  sodium  ferrocyanide  and  a  mixed  filter  residue  composed  of  calcium  sulfate  and  calcium citrate are obtained. In the second metathesis reaction, sodium carbonate is used as a conversion agent for the mixed filter residue. The optimal conditions are: a sodium carbonate to calcium citrate ratio of 3:1, 25% sodium carbonate solution, pH 10.5, a reaction temperature of 75 ℃, and reaction time 30 – 40  min.  The  filtrate  then  undergoes  two-stage  membrane  filtration,  during  which  ferrocyanide  and chloride ions are effectively retained by the membranes. Among them, sodium ferrocyanide is recycled as a raw material in the production of Prussian blue cathode materials for sodium-ion batteries, while the remaining solution is treated by reverse osmosis to remove sodium ions, and the resulting purified water  is  reused.  Meanwhile,  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 reaches over 99.6%, and sodium ferrocyanide can be directly reused in the production process under the optimized conditions. This work is expected to provide  essential  data  and  a  methodological  guidance  for  resource  recovery  and  zero-discharge wastewater treatment in the production of Prussian blue cathode materials for sodium-ion batteries.