The invention provides a method for separating quartz from low-grade potassium and sodium feldspar ore. The method comprises the steps of providing low-grade potassium and sodium feldspar ore powder; mixing the low-grade potassium and sodium feldspar ore powder and water for obtaining low-grade potassium and sodium feldspar ore slurry; adjusting the pH value of the low-grade potassium and sodium feldspar ore slurry to 8-10 through conditioning agents, and then carrying out roughing, scavenging, concentrating and drying on the low-grade potassium and sodium feldspar ore slurry for obtaining fine potassium and sodium feldspar powder and floating the quartz; adding activating agents, inhibitors and amine collecting agents in the roughing process and the scavenging process each time. The method has the advantages that the production cost is low, the requirement for corrosion prevention of equipment is low, pollution to the environment is small, and the quality of the obtained fine potassium and sodium feldspar powder meets the use standard GB/T9195-1999 of the ceramic industry.