The invention discloses an acaricide containing soybean lecithin. The acaricide is prepared from one or two of active ingredients of diafenthiuron and etoxazole and further comprises soybean lecithin,and the weight ratio of the soybean lecithin to the active ingredients in the acaricide is 1: 1-1: 600. The acaricide disclosed by the invention is excellent in effect of preventing and treating theagricultural red spider mites and long in lasting period, is safe to the crops, enables the usage amount of pesticides and the usage cost to be reduced and the pollution to the environment to be relived, delays, prevent and control the generation of the drug resistance of drugs, and has prolonged service life.