Vacuum cup

The vacuum cup comprises an inner container and a shell, the inner container comprises a titanium inner container inner layer and a metal inner container outer layer, the outer side face of the inner container inner layer is tightly attached to the inner wall face of the inner container outer layer, and the bottom of the inner container inner layer is tightly attached to the bottom of the inner container outer layer; the shell comprises a metal shell inner layer and a titanium shell outer layer, and a vacuum layer is formed between the metal shell inner layer and the metal liner outer layer; the outer layer of the titanium shell is a mouth sleeve which sleeves the mouth part of the inner layer of the shell, and the mouth part of the mouth sleeve is welded and fixed with the inner layer of the liner; or the titanium shell outer layer sleeves and surrounds the whole shell inner layer, and the opening part of the titanium shell outer layer is welded and fixed with the liner inner layer. According to the technica