The work aims to repair the defect of aluminum alloy casting by electro-spark deposition (ESD) technology. Two kinds of electrodes (ER5356 electrode and self-manufactured electrode) were used to repair the pores on the surface of aluminum alloy under the optimized electro-spark deposition conditions. The effects of ESD process, electrode materials, and deposition atmosphere on the repair layer were systematically studied. Scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) were used to characterize the microstructure and element distribution of the repair layer interface. The microhardness of repair layer was tested by microhardness meter. The Tafel curve of repair layer was tested with electrochemical workstation, and the degradation rate was tested in water bath. The degradability of the repair layer was comprehensively evaluated from the aspects of thermodynamics and kinetics. Under the protective atmosphere of argon gas, the optimal repair process parameters were frequency of 5000 Hz, capacitance of 150 μF, and deposition angle of 45°, and the heat input at this time was 0.480 J. The repair layer had a dense structure and uniform element distribution, and the component segregation was small. The microhardness of the repair layer was higher than that of the substrate due to the elimination of dendrites. The self-corrosion potential of the repaired sample (–1.493 V) was lower than that of the substrate (–1.421 V). The degradation rate of the self-manufactured electrode repaired layer was slightly faster than that of the substrate due to that the ER5356 electrode repair layer was insoluble in water. The surface defects of 3.5 inches aluminum alloy fracturing balls can be repaired by ESD technology, and the results show that the microhardness and degradability reach engineering targets.