An optoelectronic integrated substrate, a preparation method thereof and an optoelectronic integrated circuit. The electronic integrated substrate includes a base substrate and an electronic device and a photo-diode disposed on the base substrate, wherein the photo-diode includes an ohmic contact layer and an intrinsic amorphous silicon layer, and the ohmic contact layer and the intrinsic amorphous silicon layer are sequentially arranged along a direction parallel to the plane of the base substrate and are connected.