In this paper, Electro-Spark Deposition (ESD) technology was used to enhance the cavitation erosion resistance of the stainless steel. The microstructure and composition of the deposition layers were studied by optical microscope (OM), scanning electron microscope (SEM) and energy dispersive Spectrometry (EDS) on cavitation erosion resistance was investigated. The microhardness was measured too. The cavitation erosion resistance was measured in ultrasonic equipment. The preliminary study confirmed that the cavitation erosion resistance of the deposition layer was enhanced compared to the untreated substrate. Now, vane wheel made of cast-iron, stainless steel and oil bump damaged by cavitation erosion have been repaired by ESD. And the properties of the repaired vane wheels were the same as the new ones.