Connecting structure for tail gas aftertreatment

The utility model relates to the technical field of connection of tail gas after-treatment devices, in particular to a connecting structure for tail gas after-treatment. The connecting structure for tail gas aftertreatment comprises a TWC barrel and a GPF barrel, one end of the GPF barrel is provided with a connecting part (21) which extends in the axial direction and wraps part of the TWC barrel in the radial direction, and the connecting part is welded and fixed to the TWC barrel. According to the utility model, the end opening of the connecting part is radially shrunk to form the necking opening, the necking opening is attached to the outer wall of the TWC cylinder body, and the TWC cylinder body and the GPF cylinder body are connected and fixed by welding the necking opening and the outer wall of the TWC cylinder body, so that the integral structure is compact, and the problem that the installation space is limited due to higher limitation of the integral axial space size of a product is effectively solve