Recently, replacing flat substrates with patterned substrates has been considered an alternative way to improve the photovoltaic properties of layered transition metal dichalcogenides (TMDCs) materials. As an anisotropic 2D layered material, rhenium disulfide (ReS2) is a promising candidate for photodetection applications owing to its thickness-independent direct band gap and considerable anisotropy in electrical and optical properties. Herein, the multilayer ReS2 film is synthesized by CVD method and transferred to different patterned substrates. The use of the patterned substrate instead of the flat substrate improves the absorbance due to the enhancement of the light scattering effect, which has been simulated and proved by finite-difference time-domain (FDTD) simulation. The photoresponse of the prepared ReS2 on patterned sapphire and gallium nitride substrates photodetectors have been significantly enhanced under 460 nm illumination, and the improved response and photoelectric conversion efficiency may be caused by the strong electron-phonon coupling effect of the gallium nitride substrates. This work paves a technological guide for the performance optimization process of ReS2-based phototransistors in the field of optoelectronics.