Aluminum is a widely used corrosion-resistant material. As one of the important technologies in the field of surface engineering, thermal spraying technology can be used to prepare aluminum coatings on the surface of mild steel to provide corrosion-resistant protection, prolong the service life of mild steel, and reduce the maintenance. At present, flame spraying technology, arc spraying technology and cold spraying technology are commonly used to prepare aluminum coatings. The characteristics and corrosion resistance of aluminum coatings prepared by these three thermal spraying technologies were reviewed. The influence mechanism of heat source temperature, particle flying speed and spraying distance on the characteristics of the coatings and the corrosion resistance mechanism of the aluminum coatings in 3.5%NaCl solution were systematically summarized. It was found that the pore content in the aluminum coating was the most important factor affecting the corrosion resistance. The pore content could be expressed by the porosity and the corrosion resistance of the aluminum coating decreased with the increase of the porosity. However, the effects of different contents of pore and the different shapes and sizes of pore on corrosion resistance were not pointed out in detail. Therefore, it is of great scientific significance for the practical application of thermal spraying aluminum coatings in the future and is one of the key research directions in the future to further optimize the process of preparing aluminum coatings by thermal spraying technology and to study the specific corrosion resistance of aluminum coatings with different content of pores and pores of different shapes and sizes under actual service conditions.