The invention discloses a method for preparing nanometer silver lines in large batch. anhydrous silver nitrate AgNO3 with the concentration of 99.9percent, anhydrous glycol (C2H6O2) of 99.8percent and polyvinylpyrrolidone (PVP, with the molecular weight of 55,000) of 98percent are selected as the raw materials; in a microwave-assisting environment, the method of adopting the glycol to reduce the silver nitrate is adopted to prepare nanometer silver lines in large batch. By replacing the original solvent heating method with the high-heat environment created by microwave, the method not only greatly saves the reaction time but also reduces the preparing costs for the nanometer silver lines. The glycol, a moderate reducer, can slow the reaction, thus providing the time for the growth of nanometer silver lines. The method of the invention is the optimal method for preparing the nanometer silver line according to testing results by comparing the influence of micro strength, precursor concentration and microwave processing time on the appearance and size of the prepared nanometer lines. The method of the invention has low cost, is simple method and easily controlled and has high practical value in the application to the industrial production developing nanometer silver lines.