The work explained the formation mechanism of micro-pores in MAO processing and summarized the latest re-search progress of pore sealing technology. On the basis of different sealing mechanisms, the advantages and disadvantages of various sealing methods were analyzed, such as hydration sealing, organic sealing, inorganic sealing and some new sealing techniques. The self-sealing showed great advantages, including self-sealing based on solutions and self-sealing based on external electric field. The self-sealing technology based on solutions was achieved by optimizing the composition and formula of electrolyte, and the other self-sealing based on the external electric field drove the charged particles moving toward micro-pores to form precipitate and to seal the pores. In addition, the development trend of the sealing technology is prospected.