Automobile exhaust pipe

The invention discloses an automobile exhaust pipe. The automobile exhaust pipe comprises an exhaust pipe body, a three-way catalyst is arranged at the air inlet end of the exhaust pipe body, a spiral pipe part is arranged in the middle portion of the exhaust pipe body, and a three-way catalyst is arranged between the spiral pipe part and the air outlet end of the exhaust pipe body; an anti-backward-flowing device is arranged at the air outlet end of the exhaust pipe body and comprises a connecting part arranged at one end of the exhaust pipe body, an insertion connection groove is formed in the connecting part, and a sealing ring is arranged in the insertion connection groove and comprises a bottom ring arranged at the bottom of the insertion connection groove; a wall ring capable of being attached to the inner wall of the insertion connection groove is arranged on the bottom ring, a compression mechanism is arranged on the outer side of the insertion connection groove, and a downward waterproof stopping she