The invention relates to the field of water-treatment materials and discloses an antibacterial composite reverse osmosis membrane for high-efficiency water treatment and a preparation method. The preparation method comprises the following preparation processes of: (1) immersing a porous polysulfone supporting membrane into piperazine aqueous solution, n-hexane solution of trimesoyl chloride and glycerinum aqueous solution containing formaldehyde successively, and after taking out, preparing out a polyamide desalting layer on the surface of the porous polysulfone supporting film; (2) preparingdispersion liquid by adopting the following components in parts by weight: 25-30 parts of bacillus-natto antibacterial protein, 22-25 parts of protamine, 5-8 parts of sodium lactate and 37-48 parts ofwater; (3) after mixing the dispersion liquid and glutamine transaminase, coating on single surface of the polyamide desalting layer, drying and preparing the antibacterial composite reverse osmosismembrane. Compared with the traditional antibacterial composite reverse osmosis membrane, the antibacterial composite reverse osmosis membrane disclosed by the invention is firm in antibacterial layerand difficult in dropping, can generate bacteriostatic action for multiple strains, and is good in bacteriostatic effect, stable in bacteriostatic property and long in service life.