They have used big-pore adsorptive resin as adsorbent and sodium hydroxide solution as desilicification agent to remove silicon colloid from the water. They have got satisfactory results. The processing capacity is 100 times larger than the resin bed volume( BV) . The silicon colloid in the water after treatment is low er than 0. 5mg/ L. It meets the requirement of the chemical technology. This technique provides a new access to the removal of silicon colloid in water treatment .