The invention relates to the technical field of filter devices, in particular to a tail gas filtering device for an automobile exhaust pipe. The tail gas filtering device comprises an inserting pipe and a fixing plate, wherein the fixing plate is located at the right end of the inserting pipe and communicates with the inserting pipe, an annular clamping groove is formed in the left side of the inner wall of the inserting pipe, a circular sponge block is clamped in the inserting pipe through the clamping groove, a water storage tank which is used for containing water and is in a V-shaped shapeis arranged in the middle of the interior of the inserting pipe, and at least three communication ports used for transmitting tail gas are uniformly formed in the upper side of the outer wall of the water storage tank. According to the tail gas filtering device for the automobile exhaust pipe, when filtering is carried out, by the sponge block, the particles in the tail gas can be adsorbed in thesponge block when the tail gas blows through the sponge block, and then the tail gas enters the water storage tank through the communication ports at the left end of the water storage tank, so that the water washing operation can be carried out, harmful substances in the air are washed and filtered, and the tail gas filtered by the water washing tank is discharged from the communication ports at the right end of the water storage tank.