Concrete pump trucks can continuously transport concrete under pressure and are widely used in building, bridge, and tunnel construction. The concrete pump truck includes a conveying cylinder and a hopper, which are connected by a transition sleeve. Considering that the connection between the conveying cylinder and the transition sleeve usually bears a large frictional force, in order to prevent severe wear of the transition sleeve, the inner wall of the existing transition sleeve is usually welded with a wear-resistant layer, and the welding material is mainly flux cored wire or high chromium welding rod. The wear-resistant layer of this type of welding has unevenness and is prone to deformation and failure due to excessive extrusion force, resulting in a relatively short service life. In addition, the wear-resistant layer of some transition sleeves is composed of multiple high-strength ceramic alloy sheets bonded by strong adhesive. There are adhesive gaps between adjacent layers of ceramic alloy sheets, and the strong adhesive filled in the gaps cannot resist the erosion of concrete, resulting in some ceramic alloy sheets falling off. The service life of such wear-resistant layers is still relatively short.Compared to the background technology, the transition sleeve of the concrete pump truck provided by this utility model is connected with a hard alloy wear-resistant layer and a high chromium alloy wear-resistant layer, forming a combined wear-resistant layer. Its inner wall is smooth, and its pressure resistance is better than that of the wear-resistant layer of the weld overlay wear-resistant layer and the ceramic alloy sheet adhesive layer. Its service life is relatively long.