The invention relates to the technical field of automobile exhaust treatment, in particular to a particulate matter filter of an automobile exhaust particulate matter filtering device. The two sides communicate with a gas inlet pipe and a gas outlet pipe correspondingly. The particulate matter filter comprises a shell, a first filter element body, a second filter element body, a first heater, a second heater and a temperature sensor arranged in the shell, wherein the first filter element body and the second filter element body are located in the shell and arranged at intervals in the axial direction of the shell, and the first heater and the second heater are in contact with the first filter element body and the second filter element body correspondingly. The end, connected with the gas inlet pipe, of the shell is in a horn shape gradually enlarged towards the end away from the gas inlet pipe. According to the particulate matter filter of the automobile exhaust particulate matter filtering device and a machining method of the particulate matter filter, structural design is novel, especially, in the shell of the particulate matter filter, a protection layer is formed by pretreating the surface, and therefore the wear resistance and corrosion resistance of the particulate matter filter are improved.