Airtightness detection device for engine post-processing assembly

The utility model relates to an air tightness detection device for an engine post-processing assembly, and relates to the technical field of air tightness detection. The pressing and fixing mechanism is connected to the workbench and used for fixing the post-processing assembly; the air inlet pipe sealing mechanism is connected to the workbench and comprises an air inlet pipe sealing head, the air inlet pipe sealing head is provided with an air inlet and an air outlet which are communicated, and the air outlet is located in the middle of the sealing face of the air inlet pipe sealing head; the exhaust pipe sealing mechanism is connected to the workbench and comprises an exhaust pipe sealing head; the airtightness detection device further comprises a water leakage pipe sealing mechanism connected to the workbench, the water leakage pipe sealing mechanism comprises a water leakage pipe end socket, and the water leakage pipe end socket can be connected with the end portion of the water leakage pipe in an inserte