Abstract: To explore the regeneration performance and mechanism of the catalyzed diesel particulate filter (CDPF), an engine bench test was carried out to study the regeneration characteristics for three groups of CDPFs with catalyst loading of 0, 530(CDPF1) and 636 g/m3(CDPF2) under endurance cycle conditions in this paper. The endurance cycle tests consist of 26 operating conditions, and each test cycle lasted 5 hours, which equivalent to the vehicle traveling 800 km on the actual road. The test results showed that exhaust pressure drop across CDPF during the test was significantly lower than that of DPF. When the inlet temperature reaches 500 ℃, the pressure drop between CDPF1 and CDPF2 was about 14 kPa lower than that of DPF. From the 8th operating condition of endurance cycle to the 25th, CDPF could almost completely oxidize the trapped soot. Passive regeneration consumes NO2, and the NOx concentration of CDPF1 with 530 g/m3 catalyst loading was lower than that of the front end under heavy load conditions. The CDPF2 with 636 g/m3 catalyst loading produced higher concentration of NO2 with the increase of catalyst loading, and generated amounts of oxidation components were higher than consumed amounts of passive regeneration. Therefore, regeneration efficiency of CDPF was greatly increased compared with DPF, the regeneration efficiency for endurance cycle of CDPF1 was 87.5%, and that of the CDPF2 was 93.1%. Because the soot emitted by diesel engines have 11 kinds of polycyclic aromatic hydrocarbons, and phenanthrene is composed of 3 ring aromatics accounts for the largest proportion, so the density functional theory (DFT) in quantum chemistry was used to construct the oxidation reaction model of phenanthrene and NO2 to produce CO and CO2 on the Pt (111) crystal plane in the paper. DFT calculation results showed that O1 atom in NO2 was continuously slipped on the Pt(111) crystal plane, and chemical double bond of the N=O was gradually elongated and broken, and dissociated produced the active oxygen O1. The C=C double bond was produced by C1 and C2 atoms of phenanthrene radical, and the C-C single bond was elongated between C1 and C10 atoms. The C1 atom was dissociated from phenanthrene radical after C-C bond was broken. The dissociated C1 and active O1 atoms continued to slip on Pt crystal plane and approach each other, gradually producing a C-O single bond and finally generating CO molecule. The activation energy of C1 atom oxidized to CO was 234 kJ/mol, and reaction rate coefficient was 1.34×1018/s. When the C1 atom was completely oxidized to CO2, two NO2 molecules were required to dissociate, and produce two active O atoms which were O1 and O2, respectively. These two active O and C1 atoms were slipped on Pt crystal plane, and were close to each other to generate O=C=O chemical bond. The activation energ of C1 atom oxidized to CO2 was 218 kJ/mol, and reaction rate coefficient was 5.63×1016/s. Based on chemical reaction kinetic parameters calculated by DFT, a one-dimensional regeneration model of CDPF1 was constructed to calculate the exhaust pressure drop during passive regeneration, and the error range between simulation value and test value was within 3%. This also verified the accuracy of DFT calculation results. The study of combining engine bench test with DFT calculation of Soot-NO2 reactions, which was not only reveals passive regeneration characteristics of soot from a macroscopic perspective, but also reflected passive regeneration process of soot from a microscopic perspective. This study can provide theoretical basis and engineering guidance for improvement of CDPF regeneration efficiency.