Two-dimensional (2D) materials consist of conductors, semiconductors, ferromagnets, superconductors, ferroelectrics, etc.. It is difficult to realize specific functional applications by only one 2D materials. 2D materials can be stacked to produce van der Waals heterojunctions with specific functions, and then produce the next generation of functional devices, which has gradually become an important development direction of low-dimensional devices and semiconductor applications. Superlattices or van der Waals heterojunctions of graphene, hexagonal boron nitride (hBN) and other 2D materials, which are stacked by stripping method, can exhibit different properties such as unconventional superconductivity, anomalous quantum Hall effect, and ferroelectricity under different rotation angles. This talk mainly introduces our two recently proposed methods of stacking growth and stacking transfer for the preparation of wafer-level, high-quality 2D materials van der Waals heterojunctions, including graphene, hBN, 2D semiconductors, metals, superconductors, ferromagnets, etc., and initially explores the functional applications of 2D materials van der Waals heterojunctions.