Abstract: In this article, multi-dimensional numerical simulation in three different vector spaces for velocity and pressure field of steady flows in Catalytic Converter was performed by using computational fluid dynamic method (CFD).Simulation results show that the gap between the carriers has a great impact on the flows of the Catalytic Converter.For the carrier of the same length, when the vector space enlarges, the velocity distribution within Catalytic Converter will be more uneven and the pressure loss will slightly increase.