Two-dimensional (2D) van der Waals heterostructures and interfaces are widely researched for their potential application in next generation sensing, thermal imaging and light communication systems. Here, we demonstrated the hetero-interface induced anomalous photoluminescence (PL) emissions in the vertical WS2/Ga2O3 heterostructures. The WS2/Ga2O3 hetero-interface varies type-II band structure and brings subsequent PL decline in the bottom WS2 monolayer contacted with Ga2O3 layer. Such hetero-interlayer coupling interaction between oxides and 2D layered transition metal dichalcogenides (TMDs) in the stacked heterostructures impacts interlayer interaction between the bottom WS2 monolayer and the upper WS2 monolayer in a WS2 bilayer, which leads to an anomalous PL enhancement in the bilayer WS2. Stacked hetero-interface will benefit for controlling the optical or electronic behavior and modulating energy band structures by customizing transformative 2D heterostructures used in next-generation nanoscale optoelectronic detectors and photodetectors.