Electro-spark deposition technology (ESD) is widely used in the preparation of coating and the damage repair for the surface of parts. The principle of ESD was briefly introduced, and its advantages of surface strengthening and repair were summarized. The effects of the main process parameters (voltage, capacitance, specific deposition time and argon flow rate) on the deposition efficiency, morphology, defect, microstructure and properties of the coating were discussed systematically. The input and release rate of heat were the key factors among the process parameters that affected the preparation of the coating. The coating with high performance could be easily obtained under low energy input, but the deposition efficiency was low. Then, aiming at the problems of ESD, such as many cracks and holes, low deposition efficiency and uneven preparation of coating, the technical improvements made in the automation of deposition process, optimization of deposition principle and compounding with other technologies were introduced. The combination with other surface strengthening technologies was an effective way to further improve the performance of the coating, which would be one of the key research contents. Then, based on the needs of engineering practice for high-performance coatings, the application of ESD in the preparation of ceramics, high-entropy alloys and amorphous coatings were introduced. The characteristics of fast heating and rapid cooling of ESD made it show excellent ability to form fine grain, amorphous and solid solution phase in the process of coating preparation. Lastly, the problems of ESD were summarized and the future development of ESD was prospected.