A method for treating reverse osmosis concentrated water, comprises adding precipitant and oxidant to reverse osmosis concentrated water for treatment, filtering to obtain clear liquid, and adding catalyst for water treatment to clear liquid for catalytic oxidation to obtain a first-stage treated water. Optionally, the liquid may be subjected after catalytic oxidation to an adsorption treatment; performing reverse osmosis treatment on first-stage treated water to obtain second-stage reverse osmosis product water and second-stage reverse osmosis concentrated water; and adding oxidant to second-stage reverse osmosis concentrated water for oxidation treatment to obtain directly discharged effluent water. The obtaining of effluent water may further comprise subjecting liquid after oxidation treatment to adsorption treatment. The above method can recycle 75-85 wt % of water, and operates easily. Thereby, improvement to overall utilization rate of water, and treatment of little remaining water is met to effluent standard for reduction of environmental pollution and economic investment.