Abstract: The Catalytic Diesel Particulate Filter (CDPF) has become necessary aftertreatment devices to reduce diesel exhaust particulate matter emissions. When CDPF is not completely regenerated, some particles are not completely oxidized, and the structure of the deposited particle layer changes after CDPF is captured again, which changes the regeneration performance of CDPF. Based on the thermogravimetric experiment bench and the external heating source regeneration bench, the oxidation characteristics of particulate matter with different oxidation degrees are first analyzed, and it is found that regeneration will reduce the combustion index of particulate matter and increase its activation energy, and the rapid regeneration time of old particulate matter will increase with the increase of regeneration degree. At the same time, it was found that the presence of old particulate matter could significantly reduce the peak temperature inside the carrier during regeneration. At the regeneration temperature of 535 ℃ and 500 ℃, when the proportion of old particulate matter was 50%, the peak temperature of regeneration decreased the most, and the maximum decrease was 306 ℃ and 148 ℃,However, its regeneration efficiency will also decrease, with a decline rate of 6.8% and 12.4%, respectively. When the regeneration temperature was 475 ℃, the peak temperature did not occur due to the low regeneration temperature. It can be seen that CDPF can be regenerated in fractional times at high temperature to reduce the thermal shock of CDPF and play a protective role in the carrier.