Thermal conductivity characteristics of the diesel particulate filter(DPF) substrate significantly impact on the parking regeneration of diesel engines under plateau conditions. The heat transfer patterns within DPF/ catalyzed diesel particulate filter(CDPF) using two substrates with different thermal conductivity characteristics were investigated under steady flow fields，and the effect of thermal conductivity characteristics on bed temperature variations and regeneration efficiency during the parking regeneration was examined. Results show that as the DPF inlet temperature uniformly increases，bed temperatures at all positions rise linearly at faster rates in substrates with higher thermal conductivity. Higher conductivity substrates exhibit higher temperature rise rate. During parking regeneration，substrates with higher thermal conductivity exhibit greater regeneration efficiency in DPF and CDPF. Extending regeneration duration gives more regeneration efficiency improvement. Effective active coatings can substantially mitigate the low regeneration efficiency caused by substrate thermal conductivity differences in plateau environments. When using the optimized high-conductivity substrate with a carbon load of 6g/L and an inlet temperature of 580℃，the CDPF achieves a regeneration efficiency of 95.4% after a 1800s parking regeneration，meeting plateau regeneration requirements.