The invention discloses a multipoint electronic device preparation method based on a GaN level nanowire cross junction. The method comprises the steps that a substrate is cleaned, and a metal thin film is evaporated; the substrate is inverted in an HVPE device, so that one side, which is evaporated with the metal thin film, of the substrate is downward, and a gap is arranged between the side and a graphite disk below; the nanowire cross junction grows on the substrate through a VLS method; and nitromurlatic acid processing, lithography and annealing are carried out to form ohmic contact. According to the invention, the gap is arranged between one side evaporated with the metal thin film and the graphite disk to ensure that the air flow is normal; the generated level GaN nanowire cross junction is controlled to be closely connected with the substrate without the need for transfer, which enhances the performance stability of a device; in the subsequent production process, ordinary lithography is simply needed; the preparation cost is low; and the multipoint electronic device preparation method based on the GaN level nanowire cross junction can be widely applied in the field of microelectronics.