The invention provides an air leakage detection device for sealed tanks, comprising a body. The body further comprises a liquid storage tank inside. The bottom of the liquid storage tank is connected with an air testing chamber. The top of the body is provided with an electronic display device and an air bubble detector which are connected with each other. The bottom of the air bubble detector is provided with a liquid passing pipe which is connected with the liquid storage tank. The inside of the body further comprises an air bubble detection chamber. The air bubble detection chamber is internally provided with a crawler belt, and the crawler belt is provided with clamping slots. The air bubble detection chamber is further internally provided with a sealed bubble detection chamber which is connected with the liquid storage tank. An electric transmission device is connected with the crawler belt. Because the technical scheme provided by the invention is adopted, higher convenience in actual detection is realized. The air leakage detection device for sealed tanks further has the advantages of simple structure, convenient maintenance, low machining cost, high safety, high practicability, and the like.