Here， a graphene-black arsenic van der Waals heterostructure is fabricated by the fixed-point transfer technology， realizing the broadband detection from visible light-infrared-microwave. Among them， the photoexcited electron-hole pairs generated in the black arsenic are separated and injected into the graphene under visible and infrared light radiation， which significantly reduces the potential barrier between the semiconductor black arsenic and the gold electrode， thereby realizing effective photocurrent extraction. In the microwave band， due to the difference in the Seebeck coefficient of the two materials， the non-equilibrium carriers are generated due to the photothermoelectric effect， forming the photocurrent under zero bias. The research results paved the way for bandgap engineering of two-dimensional layered materials to be applied to the fields of photonics and optoelectronics.