Abstract: The present invention relates to the field of semiconductor technology and provides a method for forming an MEMS cavity structure, which can improve process yield for MEMS integration and encapsulation for functional stability and reliability of the MEMS structure. The method includes steps of: forming an adhesion material layer on a bottom layer; forming a bottom layer on a substrate; forming a adhesion material layer on the bottom layer; forming a support structure and a sacrificial layer that is filled in a space surrounded by the support structure on the adhesion material layer; forming a capping layer on the support structure and the sacrificial layer, and the bottom layer, the support structure and the capping layer together defining a cavity; and releasing the sacrificial layer and the adhesion material layer to form the cavity structure.