Abstract: The forward osmosis membrane and the preparation method thereof provided by the present invention, through fully cover the support mesh layer of the membrane with antibacterial nanoparticles, especially the mixture of nano-Ag and nano TiO2, ensures without reducing the strength, water flux and salt rejection, providing an effective, long-term and comprehensive antibacterial effect. In the present invention, the antibacterial nanoparticles, especially the mixture of nano-Ag and nano-TiO2, are used to carry out antibacterial modification on the support mesh of the forward osmosis membrane, so as to inhibit the growth of bacteria on the forward osmosis membrane, improves the forward osmosis and also improves the safety of the entire purification and filtration system. The antibacterial forward osmosis membrane of the present invention can be applied to the filtration and purification of complex water sources, especially the purification and filtration of eutrophic and bacteria-prone water sources.