Abstract: Based on culture experiment of nutrient solution, combined with chemical analysis metnods of the ICP spectrograph ,atomic absorption spectrograph ,this project studies the interaction between silicon and heavy metal (cadimium and zinc ) in the wheat ,understands the characterrstics of heavsilicion for absorption, distribution and accumulation of heavy metal in the wheat growth course and its effect of physiology and biochemistry,inquires into the pattern of transport and variation of the heavy metal under the control of silicic acids .the project for study possesses important therory and practice meanings in the basic theory research field .Test of water nurtue indicaded that 90mg/L 、60mg/L of silicon it can reduce Cadimium、Zinc plloution of wheat .However , promoted action showed raising root activity ,chilorophyll content， while the permeability of cell membrance of decreased .From the facts above ,it can be shown that silicon concentration was controlled in a certrain limit can promote the growth of wheat ,and meanwhile ,it can also protect the cell of wheat ,reduce heavy metal plloution of wheat .However ,high concentration and low concentration of silicon can be harmful to the cell of wheat .