NOVELTY - An anisic aldehyde is prepared by placing estragole in isomerization container, adding potassium hydroxide, controlling isomerization container temperature at 175-185 degrees C, reacting for 3-5 hours, stopping heating when reaction is complete to obtain anethole, freezing anethole at less than or equal to 20 degrees C, centrifuging to obtain high purity anethole, placing high purity anethole in reaction container, adding dilute sulfuric acid and manganese dioxide, controlling reaction container temperature at 80-110 degrees C, reacting for 2-6 hours to obtain crude anisic aldehyde, centrifuging, and washing with water and brine.    USE - Preparation of anisic aldehyde for perfume.    ADVANTAGE - Preparation method is simple and environment-friendly, has improved yield, short production time, and reduced production cost, promotes easy purification, reduces wastewater discharge, and prevents corrosion and prolongs service life of device.    DETAILED DESCRIPTION - An anisic aldehyde is prepared by placing estragole in isomerization container, adding potassium hydroxide, controlling isomerization container temperature at 175-185 degrees C, reacting for 3-5 hours, stopping heating when reaction is complete to obtain anethole, freezing anethole at less than or equal to 20 degrees C, centrifuging to obtain high purity anethole, placing high purity anethole in reaction container, adding dilute sulfuric acid and manganese dioxide (MnO2), controlling reaction container temperature at 80-110 degrees C, reacting for 2-6 hours to obtain crude anisic aldehyde, centrifuging, washing with water and brine, and performing secondary washing with baking soda in water to obtain anisic aldehyde crude product with alkaline pH in which amount of added potassium hydroxide is 3-10% of mass of estragole, amount of high purity anethole placed in reaction container is 1000 pts. wt., amount of dilute sulfuric acid is 100-300 pts. wt., and amount of MnO2 catalyst is 200-500 pts. wt., brine is 2-10 mass% chloride salt obtained by mixing chloride and water where chloride is sodium chloride or potassium chloride, and amount of baking soda solute in water is 2-20 mass%.