The invention relates to a method used for liquid phase synthesis of germanium nanowires. The method comprises following steps: GeI4 is taken as an germanium source, and is dissolved in oleylamine; gold nanoparticle is taken as a catalyst, and is added; reaction is performed at a temperature of 320 to 350 DEG C without water or oxygen; the obtained product is filtered, and washed with ethanol or n-hexane, the filtering-washing procedure is repeated for another two times, and then the product is dried in a vacuum drier at room temperature so as to obtain the germanium nanowires. The method is different from traditional solid phase method-chemical vapor deposition, synthesis temperature is low, technology is simple, and cost is low.