Because of their special physicochemical properties, pore-structured metal oxide catalysts are widely used in environmental catalysis, energy chemicals, fuel cells, medicine, and other related fields. In recent years, these oxides have also been increasingly studied in the catalytic purification of diesel engine exhaust gases. In this paper, the research progresses of preparation methods of porous metal oxide catalysts and their application in the catalytic purification of diesel engine exhaust were reviewed. The advantages and disadvantages of different methods for the synthesis of porous metal oxide catalysts were elaborated, as well as the mechanism comparison of different types of porous metal oxide catalysts in catalytic purification of diesel engine exhaust pollutants. Finally, the current issues on the preparation of porous metal oxide catalysts and their development trends in application of diesel engine exhaust purification were summarized and discussed. The pore-structured metal oxide catalysts are beneficial for improving the contact efficiency between catalysts and pollutants, which can enhance the catalytic purification efficiency of catalysts. Meanwhile, the intrinsic activity is the most fundamental factor for determining their catalytic activity except for porous structure effects. In addition, this paper can help researchers to deeply understand the important effect of porous metal oxide catalysts in the treatment of diesel engine exhaust pollutants and provide theoretical guidance for the design and development of high-efficiency catalysts.