The invention relates to a light / ozone-electricity-adsorption reaction device and method for extracting copper by degrading browning waste liquor. The device comprises a light / ozone synergistic decomposing device, an electrolysis device for degrading and recovering metal copper and an adsorption elution device. In the device, a photocatalyst and an oxygen catalyst are loaded on a porous activated carbon carrier with high specific surface area; under the synergistic effect of ultraviolet light and ozone, photo-generated electron pairs are prevented from compounding, long-time catalytic treatment activity is kept, a free radical.OH with strong oxidation activity is generated, organic matters in the browning waste liquor can be oxidized and degraded, and the complexing bond of the complex in the browning waste liquor can be broken; insoluble reticular titanium base material serves as an anode, a copper sheet material serves as a cathode, organic matters in the browning liquor is continuously degraded by electrolysis to generate a second-grade degrading product which is easy to adsorb, and valuable metal copper is recovered on the cathode; and finally, common activated carbon is used for adsorbing to effectively treat the browning waste liquor, so as to realize green and environment-friendly treatment of the browning waste liquor.