The invention relates to a low-cost low-pollution gallium nitride (GaN) nano-wire preparation generation method, and belongs to the field of inorganic compound semiconductor materials. The method provided by the invention comprises the steps that: (1) GaN powder is subjected to gum-doping, grinding, tabletting, and calcining, such that a GaN target is prepared; (2) a washed and bake-dried silicon wafer is deposited for 30-60s by using a SBC-12 small ion sputtering instrument, such that a substrate with a gold film with a thickness of 10-30nm on the surface is obtained; and (3) a plasma-assisted hot-wire chemical vapor deposition method is utilized, wherein an atmospheric pressure is 1500Pa-2500Pa, a substrate temperature is 800-1000 DEG C, a bias current is 100mA-180mA, a flow rate of fed nitrogen is 10-50cm<3>/min, a flow rate of fed hydrogen is 10-50cm<3>/min, and a deposition time is 5-30min. With the method provided by the invention, solid and linear gallium nitride nano-wires can be obtained. The product is straight, neat, ordered, uniform, and linear. Chemical and physical properties of the nano-wires are stable. The preparation process is short, and product growth is fast. Product diameter reaches 40-150nm, and an average single wire length is 10-15mum.