Abstract: Biofilm can adsorb and degrade pollutants, plays an important role in water treatment. It is the representative of water purification. The study of effections about hydrodynamic force to biofilm in water can supply important bases for improving the purification performance of biofilm and the self-purification of water. The research progress on the effections about hydrodynamic force to biological membrane purifycation ability in water were introduced in the article. It included three impacts which were the effects on the community structure, morphological structure and mass transfer ability. Besides, future research directions were put forward.