The invention relates to a
reverse osmosis membrane and a preparation method thereof, and the preparation method comprises the following steps: immersing a
polysulfone-based membrane into a
dopamine-containing
mixed solution, and carrying out constant-temperature oscillation to form a
dopamine pretreatment layer so as to obtain a modified base membrane; dissolving
rosmarinic acid ester modified m-phenylenediamine,
piperazine, a surfactant, an auxiliary agent and a pH
regulator in water, and stirring for dissolving to obtain a water phase solution; dissolving an
acyl chloride monomer in an
organic solvent, stirring and dissolving, then adding the modified
titanium dioxide, and carrying out
ultrasonic dispersion to obtain an
oil phase solution; immersing the modified base membrane into the water phase solution, taking out the modified base membrane, immersing the modified base membrane into the
oil phase solution, taking out the modified base membrane and
drying the modified base membrane to obtain a pre-compounded
reverse osmosis membrane; and carrying out post-treatment on the pre-compounded
reverse osmosis membrane to obtain the reverse
osmosis membrane. Under the condition that the water yield is guaranteed, the reverse
osmosis membrane disclosed by the invention has a high
desalination rate and the
oxidation resistance of the reverse
osmosis membrane is improved for a long time.