In this paper，API filtration experiments were carried out to study the influence of silica nanoparticles with amino （SiO₂-A），double bond（SiO₂-D）and epoxy groups（SiO₂-E）on the filtration of water-based drilling fluid and their compatibility with commercial filtrate reducer，including phenolic resin，sulfonated asphalt，low viscosity CMC and potassium humate. And the molecular structure of surface modifiers，morphology and hydrophilic/hydrophobic properties of nanoparticles were studied by means of infrared spectrometer，transmission electron microscope and contact angle measuring instrument，respectively. The results showed that the filtrate loss of drilling fluid was reduced by 41% and 29%，respectively，compared with adding commercial filtrate reducer alone，when SiO₂-D was combined with low viscosity CMC and potassium humate at mass ratio of 2∶1 and 1∶1， respectively. After aged at 180 ℃，SiO₂-D still had good compatibility with humic acid potassium，and the filtrate loss of the drilling fluid adding SiO₂-D and humic acid potassium was 28% lower than that adding humic acid alone. The reason for the good compatibility between SiO₂-D and potassium humate was that the polar groups in potassium humate，such as —OH，—OCH₃， =CO，could implement the hydrogen bond adsorption with hydroxyl groups on the surface of SiO₂-D，which could stabilize the viscosity of drilling fluid and maintain the particle size distribution of solid phase in drilling fluid. Ultimately，thin and dense mud cake in the filtration process was formed， so as to effectively control the API filtrate loss of drilling fluid.