One acidic solid catalyst (SiO2-IL) was successfully synthesized through immobilization of SO3H-functionalized ionic liquid by chemical bonding grafting, using 1, 3-propane sultone and thiolated nano-silicon dioxide as raw materials. The structure and thermal stability of the catalytic materials were characterized by NMR, FTIR and TG. Esterification of methanol with oleic acid was carried out by using this solid acidic catalyst. We find that the acidity of SO3H-functionalized ionic liquid and the stability of chemical bonding grafting are the key points and reasons to decide the catalytic performance of the solid catalyst. Moreover, the reaction conditions of reaction temperature, reaction time, molar ratio of reactants and the catalyst amount were optimized. The results show that under the optimized reaction conditions of 60 ℃, n (methanol):n (oleic acid)=12:1, 5 h, m (cat.):m (oleic acid)=0.09:1.00, the yield of methyl oleate was 94%. After reusing this acidic solid catalyst 6 times, the yield of methyl oleate still can be over 74%.