Abstract：The effects about immobilization of bacteria on functional silicon covered mesoporou magnetic carriers were investigated, including the effects of adsorption time, input quantity, temperature, pH value, et al. The immobilization results of functional silicon covered mesoporou magnetic carriers were compared with those of unfunctional silicon covered mesoporou magnetic carriers. It is shown that when at the temperature of 30℃, pH=7,shaking at 200r/min for 24 hours, the result about immobilization of bacteria would be the most suitable. The tentative application in domestic wastewater was also studied, and the most suitable condition is pH＝7，treating for 24h，input quantity of 0.5g. Under this condition the removal ratio of CODCr can reach 82.7％. The used functional silicon covered mesoporou magnetic carriers can recovered by washing in HCl liquid, and then the result of treatment of domestic wastewater can still reach 75.1％.