In this work, volcanic rocks were used as particle electrodes to construct a volcanic rock three-dimensional (3D) electrode reactor. In a wide pH range (3 ~ 11), volcanic rocks can degrade norfloxacin (NOR) at low voltage (4 V) within 40 min. In acidic environment, the NOR removal was greater than 85%. Volcanic rock also showed excellent electrocatalytic activity when treating ofloxacin, methylene blue and other pollutants. After six cycles, the weight loss rate of volcanic rocks was 3.87%. Volcanic rocks had high mechanical strength stability. There were hydroxyl radicals (OH) and superoxide radical (O2−) produced in the volcanic rock 3D system. The volcanic rock surface was the main location of NOR degradation. The possible degradation mechanism and the degradation pathway of NOR were proposed. In addition, volcanic rock also showed excellent effects in actual surface water treatment.