Engine exhaust pipe thermal shroud

The utility model discloses a heat insulation cover of an engine air outlet pipe. The utility model comprises a heat insulation cover shell body, which is fastened outside the engine air outlet pipe through a connecting device. A cooling water chamber is mounted inside the heat insulation cover shell body; a water inlet and a water outlet are mounted on the heat insulation cover shell body; the water inlet and the water outlet are respectively on both ends of a circulating water chamber; the circulating cooling of cooling water is processed in an internal chamber of the heat insulation cover through two water inlet and outlet pipes. The utility model has a simple structure, an easy processing and a good heat insulation effect, which is convenient for mounting with a low manufacturing cost. A whole covering structure also beautifies an overall unit of the engine, and if the engine is used on a boat, the heat insulation cover can fully utilize circulation of natural resources such as seawater to cool a surface