The invention provides a synthetic method of a silver nanowire. The method comprises the following steps that a, polyvinylpyrrolidone is dissolved in an alcohol solvent, the temperature is controlledto be below 40 DEG C, silver nitrate and chloride are added to be evenly mixed, and a mixed solution is obtained; and b, the mixed solution obtained in the step a is sealed and is subjected to the reaction, and the silver nanowire is obtained. Compared with the prior art, the synthetic method of the silver nanowire adopts the specific raw material, the specific synthetic steps, conditions and parameters are combined, mutual effect is achieved, and through one-step reaction, large-scale synthesis of the silver nanowire is achieved. The method is simple, the obtained silver nanowire is uniform in size, the foundation is provided for subsequent functional application, the experiment result shows that the conversion efficiency of the synthetic method is 69.85% to 88.5%, the concentration of the silver nanowire in the solution is 5.54mg/mL to 7.025mg/mL, the diameter of the silver nanowire is uniform, and is about 40 nm, the method can be further applied to preparing of silver nanowire inkused for a conductive circuit, and the development prospect is wide.