A silica/poly (octadecyl methacrylate-co-methyl methacrylate-co-butyl acrylate) (SiO2/P(SMA-co-MMA-co-BA)) resin was synthesized by suspension polymerization method to adsorb chlorinated hydrocarbons from wastewater. The effects of particle size of unmodified SiO2 and the dosage of modified SiO2 on the adsorption properties of the resin were investigated by single factor experiment. The structure and surface morphology of the material were characterized by FT-IR, interface parameters, SEM and BET. The results showed that the resin had strong adsorption selectivity for chlorinated hydrocarbon, and when the particle size of the unmodified SiO2 is 50 nm, the dosage of modified SiO2 is 1.5% of the total mass of acrylate monomer, the modified resin within 6 h of CH2Cl2, CHCl3, CCl4 and C2Cl4 could achieved 49.10, 56.41, 46.50 and 43.45 g/g, which was 62.91%, 49.23%, 42.86% and 54.08% higher than that of the unmodified resin. After 10 cycles of adsorption and desorption, the adsorption capacity of the modified resin for CHCl3 is still 50.30 g/g, and the regeneration capacity of the modified resin was 42.21% higher than that of the unmodified resin.