A high-oil-absorption resin of a ternary copolymer for the absorption of oil spills was successfully prepared by suspension polymerization, and characterizations of the oil-absorption resin were also examined in this study. The high-oil-absorption resin, a ternary copolymerized long-chain polyacrylate with styrene (St), butyl methacrylate (BMA), and stearyl methacrylate (SMA) as the monomers and synthesized by suspension polymerization, was introduced. The oil-absorption resin of St/BMA/SMA was characterized by Fourier transform infrared spectrometry. The particle morphology of the resin was observed by scanning electron microscopy. The effects of different polymerization technological parameters, such as the mass ratios of the monomer, the benzoyl peroxide initiator, and the crosslinking agent of divinylbenzene; the sort and concentrations of the dispersing agent of hydroxyl ethyl cellulose, sodium dodecyl benzene sulfonate, and gelatin, and the polymerization temperature, on the oil absorbency of St/BMA/SMA are discussed in detail. The optimum polymerization conditions of the St/BMA/SMA copolymer were obtained as follows: mSt/mmonomer = 50 wt %, mBMA/msoft monomer = 60 wt %, mwater/moil = 3:1, mDVB/mmonomer = 1.0 wt %, mBPO/mmonomer = 1.5 wt %, mHEC/mmonomer = 0.07 wt %, mSDBS/mmonomer = 0.03 wt %, mgelatin/mmonomer = 0.14 wt % (where m is the mass), temperature = 85°C. With increasing content of these factors, the oil absorbency increased at first and then decreased. Compared with binary copolymer St/BMA prepared in previous research, the highest oil absorbencies to dichloromethane were 12.80 and 23.00 g/g in the St/BMA and St/BMA/SMA copolymers, respectively. St/BMA/SMA had a higher oil absorbency and faster oil-adsorbing rate than St/BMA. The oil absorption in the oil–water mixture and the recovery of the resin were also studied in detail. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40180.