The invention discloses a method for preparing nylon yarns. The method comprises the following steps: mixing, blending, spinning, cooling and then winding an organic copper complex, color masterbatches and PA6 slices into bobbins, wherein the organic copper complex is obtained after a coordinated ionic liquid reacts with copper powder oxidized by an oxidant, and the color masterbatches are obtained through blending granulation of the PA6 slices, germanium powder slurry and modified negative ion far-infrared powder. The method has the beneficial effect that the nylon yarns obtained by the preparation method are healthier and safer to the human body.