The moiré superlattice structure has become a subject of intense interest due to its unique and intriguing properties. Key to the success of its applications is the precise manipulation of morphologies that determines the ultimate functionalities. To achieve such a goal is, however, very challenging. In this work, we present an approach for tuning moiré superlattices of suspended van der Waals structures through out-of-plane deformation. By studying the influence of out-of-plane deformation on interlayer sliding and atomic reconstruction in bilayer van der Waals structures, it is observed that interlayer sliding can overcome van der Waals potential barriers, resulting in stacking mode variations. Detailed analysis show that contraction and rotation of moiré patterns are induced, and leads to changes in the wavelength of the moiré superlattice. The approach outlined here offers opportunities for controlling and manipulating moiré superlattices.