Pores are common in the thermal barrier coatings (TBCs), and its existence has both advantages and disadvantages on performance of TBCs. Formation mechanism of pores in ceramic layer of TBCs was analyzed comprehensively. Regulating methods of pore structure on TBCs were summarized. The effects of pore structure characteristics on heat insulation performance and mechanical properties of TBCs were investigated. The introduction of pore structure would degrade mechanical properties and thermal conductivity, and improve heat insulation effect. Pore structure characteristic parameters included pore shape, distance, slant angle and aspect ratio were proposed. Pore slant angle and aspect ratio were of great significance to thermal conductivity of TBCs, which were also key characteristic parameters of pore structure. The pore structure of TBCs could be regulated by retaining porous structure of original powder, collocating pore-forming with pore formers (organic pore former, inorganic pore former), adjusting preparation processes (critical plasma spray parameter, particle flatness ratio) and treating pores subsequently. The mechanical properties and heat insulation performance shall be adjusted to guarantee effective life of TBCs. High performance and reliable TBCs with pore structure can be prepared based upon structure characteristic design and distribution control of porous structure of TBCs.