The invention discloses a pilot heating device and method used for an internal combustion machine tail gas purification post-processing system. The device is characterized in that a particulate matter collector (200) is mounted at the upstream portion of a catalyst or catalytic filter (1000), and is internally provided with an ignition combustion device (300); according to the method, the input heat of the ignition combustion device (300) in the particulate matter collector (200) is used for igniting particulate matter collected in the particulate matter collector (200), heat generated by particulate matter combustion in the particulate matter collector (200) is used for heating the catalyst or catalytic filter (1000) at the downstream portion, and the catalyst heats up or regeneration of the catalytic filter is caused. According to the device and method, the requirement of the post-processing system for external input heat during engine exhaust heating can be greatly reduced, and therefore energy consumption is greatly reduced, design of the post-processing system and matched systems is simplified, and economy, reliability and safety of the whole post-processing system can be obviously improved.