Disclosed is a method for preparing silver nanowire. The method includes: providing a first solution and a second solution; mixing the first solution and the second solution to obtain a third solution including a plurality of silver nanowires; and performing a purification procedure on the third solution to obtain the silver nanowires. Particularly, the first solution includes a capping agent dispersed in a first alcohol solvent, and the second solution includes a silver salt and a metal precursor dispersed in a second alcohol solvent, wherein the metal precursor has a formula: MXn or MXn.m(H2O) wherein M is Cu2+, Sn4+, or Ni2+, X is Cl−, Br−, I−, SCN−, SO42−, NO3−, or C2O42−, n is 1-4, m is 1-6, and M has a valence equal to the absolute value of the product of n and a valence of X.