The invention provides a seed treating agent capable of shortening germination time of insect-resistant cotton seeds. The seed treating agent is prepared from, by weight, 90-110 parts of spring water, 1.5-2.5 parts of tea saponin, 1-2 parts of purple sweet potato anthocyanin, 1-2 parts of compound sodium nitrophenolate, 1.5-2.5 parts of table salt, 4-6 parts of alanine, 3-5 parts of monopotassium phosphate, 1.5-2.5 parts of highland barley wine, 1.5-2.5 parts of alga micro-powder, 1-2 parts of portulaca oleracea extract, 1.5-2.5 parts of armoise commune ash, 0.4-0.6 part of polydextrose, 0.4-0.6 part of glyceryl behenate, 1-2 parts of witch hazel extract, 0.4-0.6 part of neutral protease, 1.5-2.5 parts of amylodextrin, 1-2 parts of garlic extract, 1.5-2.5 parts of gibberellin, 0.4-0.6 part of potassium permanganate and 0.4-0.6 part of potassium sorbate. A method is simple, actual operation is convenient, the treating fluid capable of shortening germination time has the effects of quick sterilization and seed softening within short time, the influences of bacteria and the like on seed germination are avoided, and meanwhile the seeds can be stimulated to quickly germinate in proper environments.