The suffocation technology of cross linked polystyrene (PS) spheres with bigger particle size was studied. The influence of swelling agent dichlorethane, swelling time, reacting temperature, constant temperature time, cooling dilution time for delivered particle on the suffocation effect was discussed. The chemical structure of suffocated PS was characterized with Fourier transform infrared spectra, and the important technical parameters of ionic exchange resin with bigger particle size were testing. The optimum suffocated condition obtained was that the feed ratio of PS particle and swelling agent was 1:0.45, swelling time was 2.5 h, and suffocation reaction was carried out for 8 h at 75oC, 20 h at 85 oC, and 15 h at 100 oC, respectively. Moreover, cooling dilution time for delivered particle was 25 h. The important technical parameters of ionic exchange resin with bigger particle size obtained with optimum suffocation condition were that mass exchange capacity was 4.57 mm/g (dry), volume exchange capacity was 2.35 mm/g (dry), and specific area was 29.5 m2/g.