Diesel particulate filter is an effective technology to reduce diesel particulate emissions, and its performance is closely related to catalyst loading. Based on the platform test system of heavy diesel engine, the influence of catalyst amount on the pressure drop, gas state and particulate emission reduction performance of diesel CDPF regeneration was studied. The results show that the exhaust back pressure of catalyst increases linearly with the increase of catalyst loading. When catalyst loading increases from 0 g/ft3 to 5, 10 and 20 g/ft3, the average exhaust back pressure increases from 2.94 kPa to 3.44,3.96 and 4.51 kPa, respectively. The higher the amount of catalyst, the better the emission reduction effect of the catalytic converter on CO and THC. When catalyst loading increases from 0 g/ft3 to 5, 10 and 20 g/ft3, CO emission decreases from 78.94×10-6 to 71.39×10-6, 68.12×10-6 and 63.30×10-6, and THC emission concentration decreases from 57.34×10-6 to 48.31×10-6, 46.93×10-6 and 44.51×10-6, respectively. The amount of catalyst had a significant effect on NO oxidation, but not on NOx emission concentration. CDPF can achieve a reduction rate of more than 95% for PM and PN. Increasing catalyst loading improves the particulate emission reduction effect of CDPF, with a more significant improvement in the reduction effect of nucleation particles. The results of this study have important reference value for the design of high-performance CDPF.