The invention relates to the field of agricultural technology, in particular to a novel chemical cotton topping method for use in a shine early cotton region. The novel chemical cotton topping method comprises the following steps: from the seeding stage to maturation stage of cotton, spraying mepiquat chloride onto leaf surfaces for performing basic conventional chemical control; when the plant heights are 55-65 centimeters and the fruit branch quantity is 6-8 at the cotton maturation stage, spraying a chemical topping aqueous solution onto the top of cotton plants, wherein the chemical topping aqueous solution comprises the following components in parcentage by weight: 15-20 percent of mepiquat chloride soluble powder, 5-10 percent of Tuyouta cotton topping aqueous solution and 70-80 percent of water, and the using amount of the chemical topping aqueous solution is 40-50ml per mu. Through mechanical spraying and topping, the effects of topping and regulating plant growth are achieved, plant growth is inhibited, the labor force and labor intensity are reduced, the topping efficiency is increased, the topping cost is reduced, the yield is increased, and full-mechanical cotton production can be realized instead of manual topping.