NOVELTY - A rare earth doped zinc oxide nanowire preparing method involves adding sodium hydroxide or potassium hydroxide solution with diethanolamine to obtain mixed solution, followed by mixing solution of zinc nitrate hexahydrate and sodium hydroxide solution to obtain precursor solution of zinc nitrate. The precursor solution is mixed with rare earth element compound to obtain zinc nitrate-rare earth element compound precursor solution, which is heated with sodium hydroxide solution, followed by centrifuging sample to obtain white powder, which is dried and coated on an aluminum oxide ceramic pipe.    USE - Method for preparing rare earth doped zinc oxide nanowire for use in gas sensor that is utilized for detecting ethanol at different working temperature and a solar cell photoanode.    ADVANTAGE - The method enables preparing rare earth doped zinc oxide nanowire with uniform diameter distribution, better stability for gas sensor in simple manner, and provides the gas sensor with high response ratio and short response time.    DETAILED DESCRIPTION - A rare earth doped zinc oxide nanowire preparing method involves adding 0.5-3 M sodium hydroxide or 25 ml potassium hydroxide solution with 1-8 ml diethanolamine to obtain mixed solution, followed by mixing solution of zinc nitrate hexahydrate and sodium hydroxide solution at a 1:3-5:1 in a beaker to obtain precursor solution of zinc nitrate. The precursor solution is mixed with rare earth element compound at a 100:10:100:4 to obtain zinc nitrate-rare earth element compound precursor solution. The zinc nitrate-rare earth element compound precursor solution is heated with sodium hydroxide solution at 60-90 degrees C for 20 minutes, followed by maintaining the temperature for 30 minutes, centrifuging sample to obtain white powder. The white powder is dried at 40-80 degrees C and coated on a aluminum oxide ceramic pipe uniformly. The pipe is welded at 200-400 degrees C and subjected to aging temperature to obtain a finished product.