The invention discloses a mugwort essence oil synergistic chlorpyrifos microcapsule with a soil caking resisting function and a preparation method thereof. The mugwort essence oil synergistic chlorpyrifos microcapsule is characterized in that the microcapsule is prepared from the following raw materials in parts by weight: 1 to 2 parts of sodium pyrophosphate, 15 to 25 parts of chlorpyrifos active compound, 30 to 50 parts of bentonite, 2 to 3 parts of rice bran, 3 to 8 parts of mugwort essence oil, 30 to 40 parts of urea, 60 to 70 parts of formaldehyde, a proper amount of hydrochloric acid, 2 to 3 parts of silicon dioxide, 10 to 20 parts of methyl alcohol, a proper amount of sodium hydroxide, 2 to 5 parts of sodium hydrated poly (styrene-alt-maleic anhydride), 2 to 3 parts of sodium polyacrylate and 250 to 800 parts of distilled water. The bentonite is introduced as a carrier into the microcapsule, the purpose of delaying chemical release is achieved, the stability of a microcapsule suspending agent is improved, and the service life of the farm chemical is prolonged; and bentonite treated with the sodium pyrophosphate can be used for preventing soil caking.