The present application discloses a composite reverse osmosis membrane and a preparation method thereof. The method includes: uniformly mixing fluorine-containing polyaryletherketone of a certain concentration and silane-modified polyaryletherketone as a casting solution; coating a non-woven fabric, i.e., a substrate, with the casting solution to form a support layer; then coating the surface of the support layer with a solution A and a solution B sequentially for reaction to form a polyamide desalination layer; and coating the polyamide desalination layer with a modified polyvinyl alcohol anti-pollution layer. By means of the method, the composite reverse osmosis membrane is prepared. Compared with the prior art, the present application can prepare a composite reverse osmosis membrane with high temperature resistance and high strength by using the composite modified polyaryletherketone as the support layer, and moreover, uses polyvinyl alcohol as a component of the anti-pollution layer, and has good anti-pollution properties.