The converters with two catalysts in every one were prepared and their catalytic activity and anti-aging ability were studied with the distribution changes of palladium and rhodium contents on the two substrates. The results show that the two metals distribution influences the converter activity and anti-aging ability significantly, and for the different converters, a higher content of Palladium in the catalysts all near to the inlet or the outlet is more helpful to enhance the converter catalytic activity and anti-aging ability. For the same converter, the performances were higher when the catalyst loading more Palladium is near to the inlet, but without obvious performance advantage for the converter with same Pd/Rh ratio on the two substrates. It is indicated that designing a precious metals distribution reasonably on the two substrates is very important for increasing the using life of single converter with two substrates and controlling the vehicle exhaust emission effectively