The invention discloses a vacuum cup with a
metal shell and an inner container directly compounded and a preparation method. The vacuum cup comprises a
metal shell, an inorganic non-
metal inner container and a
transition layer located at openings of the metal shell and the inorganic non-metal inner container. The
transition layer is at least one of a metal
transition layer, a metal solder transition layer or a glass solder transition layer, the
thermal expansion coefficient of the transition layer is between the
thermal expansion coefficient of the metal shell and the
thermal expansion coefficient of the inner container, and the thermal expansion coefficient meets the metal shell gt; a transition layer gt; an inorganic
nonmetal liner; when the transition layer is a metal transition layer, the relative difference K between the transition layer and the thermal expansion coefficient of the metal shell is less than 60%; when the transition layer is a metal solder or glass solder transition layer, K is less than 20%; the
total thickness of the transition layer is smaller than 1 mm. By reasonably controlling the material and thermal expansion coefficient of the transition layer, a middle structure with a deformation inhibition function is formed, thermal expansion deformation of the metal shell is relieved, the
welding stress is reduced, the
cracking risk is reduced, and reliable and direct compounding of the metal shell and the inorganic
nonmetal inner container is achieved.