Cold spray is a new surface modification technology based on aerodynamics developed in recent years. Due to its low temperature, cold spraying has many advantages over thermal spraying. Therefore, it has become a useful means to research and develop amorphous, nano-, and other temperature-sensitive materials and it has an important application prospect and value in industry and national defense in the future. The principle, characteristics and application of cold spray in protective coating, functional coating, near net shape and parts repairing were briefly introduced in this paper. The research of coating deposition mechanism has important theoretical significance to cold spray technology, and provides important guidance for the optimization of process parameters and the preparation of premium coating. Cold spraying equipment is crucial for the improvement of coating quality and spraying efficiency, and it is essential for the transition of for the research of cold spraying technology from theory research to experimental research and finally the transformation from lab research to industry application. The deposition mechanism and research progress of cold spray were elaborated in detail. The principle and research status of the cold spray equipments such as vacuum cold spray, laser-assisted cold spray, pulsed gas cold spray and shock tunnel produced cold spray were systematically explained.