The present invention relates to a preparation method of polyurethane anti-bacterial aromatic microcapsule. Its raw material includes oil phase and water phase, in which the oil phase is formed from polyisocyanate, essence, inorganic anti-bacterial agent and cyclohexane, and the water phase is composed of sodium hydroxide, sodium alginate and deionized water. Its preparation method includes the following several steps: adding polyethylene glycol and acetone into oil phase, mixing them and drop-adding the obtained mixture into water phase for 1.5-2hr, stirring speed is 400-600 rpm at 40-60deg.C, after the drop-addition is completed, heating to 50-70deg.C, making reaction for 1-1.5hr, filtering the obtained product so as to obtain the invented product white emulsion. The grain size of said microcapsule prepared by using the invented method is 20-4 micrometers. |