Abstract: Quartz sand filtration was used for purifying the NHD (a decarburizing/desulfurizing reagent mainly consisting of polyethylene glycol dimethyl ether，developed by Nanjing Chemical Industry Company). The operating conditions，including operating pressure，filtration rate，quartz sand particle size，sand bed thickness were studied. The suitable conditions of quartz sand filtration using for purifying the NHD decarburizing/desulfurizing solution were studied，and sand-bed backwashing method and its intensity were determined. The experimental results showed that at room temperature，quartz sand particle size 0.60～0.80 mm，sand bed thickness 600 mm，operating pressure 0.03 MPa，filtration rate 8.1 m/h，after purification treatment of NHD solution with sand as filtration material，the solid impurities removal was up to 89.8%，and the absorption property of NHD solution remained unchanged.