High-efficiency and environmental-protection recovery method of nickel in spent electroless nickel plating bath

The invention discloses a high-efficiency and environmental-protection recovery method of nickel in spent electroless nickel plating bath. A low-temperature vacuum evaporation and concentration device is used for evaporating and concentrating electroplating aging liquid; generated steam is condensed to serve as cleaning water; the concentrated electroplating aging liquid is fed into a photoelectric catalysis device; through ultraviolet catalysis and electrochemical oxidation effects, organic pollutants in waste water are removed; and meanwhile, nickel ions in the waste water are transferred to a cathode under the effect of an external electric field, and are reduced to metallic nickel at the cathode. The method can realize recovery of the metallic nickel in the spent electroless nickel plating bath, reduces the environmental pollution caused by the electroplating aging liquid, largely reduces the operation energy consumption and the economic cost, and is excellent in environmental benefit and economic benefit