The application of the invention discloses a self-heating type automobile exhaust purifier. According to the scheme, the self-heating type automobile exhaust purifier comprises a purifying chamber, wherein the left end of the purifying chamber is communicated with an air inlet pipe, the right end of the purifying chamber is sealed, ceramic cellular boards are uniformly arranged in the purifying chamber, a thermal insulating layer is arranged on the outer wall of the purifying chamber, a vent hole is formed in the outer wall of the purifying chamber, close to the right end, and a valve is arranged at the vent hole. The application of the invention aims at providing a self-heating type automobile exhaust purifier, so that by utilizing the characteristic of high speed and high pressure during an exhaust discharging process, the exhaust can be subjected to adiabatic compression in the purifying chamber, and the temperature of the exhaust can be increased.