A series of Cu-Mn oxide catalysts were synthesized and the catalytic combustion effects of these catalysts on soot in both NO-containing and NO-free atmospheres were tested. Utilizing a copper-manganese catalyst as the core, in conjunction with a folded metal filter, an exhaust gas purification device was developed. Bench experiments demonstrate this device effectively enhances carbon smoke conversion and reduces CO and NOx concentrations in tailpipe emissions. Two kinds of explosion-proof diesel vehicles were further modified in Liangshuijing Coal mine and the changes in exhaust gas were analyzed. The results demonstrate that the installation of the purification device leads to an average CO removal efficiency exceeding 60.0%, NOx removal efficiency surpassing 50.4%, and soot removal efficiency reaching over 84.6%. This research presents an efficient solution for purifying exhaust gases emitted by explosion-proof diesel vehicles.