The invention discloses a waste heat energy recovery device for an underwater vehicle. An inner connection layer is arranged outside an underwater vehicle high-temperature shell, an outer connection layer is arranged outside the inner connection layer, a thermoelectric module is stuck on the outer surface, between the inner connection layer and the outer connection layer, of the inner connection layer, and a heat insulating layer fills a position between the inner connection layer and the outer connection layer. The thermoelectric module is utilized to be stuck at a position between the outside of the underwater vehicle high-temperature shell and the outer connection layer, then isolation is performed by virtue of the heat insulating layer, an underwater vehicle shell is taken as a high temperature surface, heat is conducted to a heat surface of the thermoelectric module by virtue of a connection surface, a water layer provides a low temperature surface for the thermoelectric module byvirtue of the connection surface, the thermoelectric module converts temperature difference of a high temperature end and a low temperature end into an electrical parameter and outputs the electricalparameter, a fact that a hot spot of the thermoelectric module is far away is utilized, and waste heat of the underwater vehicle is converted into electric energy to be recycled. The device disclosedby the invention is simple in structure; the thermoelectric module does not contain a moving part, thus a recovery structure is stable; and the waste heat of the vehicle is converted into the electric energy, thus energy utilization efficiency of the underwater vehicle is improved.