The invention provides a method for preparing conductive glass fibers through a chemical reaction method. Glass fibers are subjected to surface treatment by adopting vacuum plasmas, glass fibers treated through the plasmas are soaked into a carboxylation chitosan aqueous solution, taken out to be soaked into a glutaraldehyde solution, taken out to be fully rinsed with water and dried, and then glass fibers subjected to surface modification through carboxylation chitosan are obtained; the glass fibers subjected to surface modification through carboxylation chitosan are placed into a copper sulfate pentahydrate aqueous solution to be soaked, a sodium thiosulfate aqueous solution is added, the glass fibers are taken out after reacting to be rinsed with water and dried, and then the cuprous sulfide-glass fiber composite conductive fibers are obtained. The conductive glass fibers are prepared by adopting the method, the adopted equipment investment cost is low, operation is easy, the reaction conditions are mild, the applicability is high, the treatment effect is good, little fiber performance loss is generated, the quality is reliable, environmental pollution can be reduced, and the method is suitable for industrialized production.