Abstract: The present disclosure discloses a citrus fruit coloring retardant, and the citrus fruit coloring retardant is a prepared indole-3-acetic acid solution with a concentration of 1,000 ?M. The citrus fruit coloring retardant is prepared by weighing 3.504 g of indole-3-acetic acid powder, dissolving the powder in 10-15 mL of absolute ethanol, adding an obtained indole-3-acetic acid absolute ethanol solution to 20 L of sterilized distilled water, and mixing evenly to obtain the retardant. In addition, the present disclosure also provides a use method of the citrus fruit coloring retardant. The method for delaying color change of citrus fruits is reliable and stable and suitable for researches on mechanism of citrus fruits ripening in laboratory in laboratory and delay of fruit ripening in production. The citrus fruit coloring retardant is a natural plant hormone, also is low cost, environmentally friendly and non-toxic.