Based on the calculation using first-principles, we discussed adjustment for electronic properties of the GaN/graphene/WS2 trilayer vdW heterostructure by doping and biaxial strain. Mg or Se doping can regulate the band gap of the GaN/graphene/WS2 trilayer vdW heterostructure and achieve p-type or n-type dopant in graphene and the trilayer heterostructure system. Band gap decreases with the increase in positive strain, and a p-type Schottky barrier is always maintained. As the negative strain increases, the band gap reaches its maximum at ε = − 3% and then gradually decreases. And after |ε| ≥ | − 5|%, it changes to an indirect band gap. When |ε| ≥ | − 7|%, the Schottky contact type changes from p-type to n-type. Electrons are transferred from GaN layer to graphene and WS2 layer, and transfer increases with the increase in strain from negative to positive. More electrons are transferred to WS2 with positive strain, and more electrons are transferred to graphene with negative strain. The results will provide valuable information for the design of trilayer Schottky devices.