The present invention discloses a functionalized 
silicon coating mesoporous magnetic carrier. The carrier is a compound magnetic carrier having a core-shell structure formed by 
coating the magnetic ferroferric 
oxide with the 
silicon dioxide and an active amido or mercapto is bonded on the surface of the magnetic carrier and the active amido or mercapto can apply the selective 
chemisorption effect to the target chemical. The present invention simultaneously discloses a preparation method for the carrier, which in particular is that the thickness and uniformity of the 
silicon film are increased through two times of silicon 
coating processes so as to effectively protect the magnetic carrier from being corroded by acid and base in the application; the template agent on the surface of the carrier is detracted with high temperature under the 
inert atmosphere and the porecreating 
processing is applied to the surface of the carrier so as to increase the 
effective surface area of the carrier and enhance the 
processing performance. The fixed active bacterium for the funtionalized silicon coating mesoporous magnetic carrier can be applied in the treatment of the urban domestic 
sewage delivers good 
treatment effect and has important meaning to the environment protection.