Preparation method of nano-silver particles and nano-silver particles prepared through same

The invention provides a preparation method of nano-silver particles and nano-silver particles prepared through the preparation method. The preparation method comprises the following steps that a first solution is provided, wherein the first solution contains agarose dispersed in a first solvent; a second solution is provided, wherein the second solution contains silver salt dispersed in a second solvent; the first solution and the second solution are mixed, cooled and placed to obtain agarose/nano-silver plural gel; and the nano-silver particles are obtained by being separated from the agarose/nano-silver plural gel. In the preparation process of the agarose/nano-silver plural gel, the agarose is used as both a reducing agent and a stabilizing agent, no other reducing agent or additive needs to be introduced, and the agarose is safe and nontoxic; in addition, by means of an inner cavity of the agarose gel, the size of the nano-silver particles can be controlled, the nano-silver particles are prevented from being agglomerated, and the nano-silver particles with the uniform size and the controllable particle diameter are obtained.