In order to keep the excellent anti-collapse properties of silicate，and reduce or eliminate the effects of silicate on the rheology of drilling fluid system，hybrid silicon anti-sloughing agent was synthesized by surface modification with C₂H₃OSiCl₃ and then hybridization reaction with sorbitol. The rheological and anti-sloughing properties of drilling fluid prepared by hybrid silicon anti-sloughing agent and common agents were studied. The results showed that the optimum surface modified condition of silicon oxide was obtained as follows：room temperature，pH=8，2 mol/L tetraethylorthosilicate concentration and 25% C₂H₃OSiCl₃ volume fraction，2 h gel time. Hybrid silicon anti-sloughing agent had organic/inorganic hybrid structure. The rheology of hybrid silicon anti-sloughing drilling fluid was good，the effect of preventing pressure transmission was obvious，and the resistance temperature was 150℃. The collapse prevention effect of hybrid silicon anti-sloughing drilling fluid was better than that of zwitterionic polymer drilling fluid and potassium polyacrylate drilling fluid.