The invention relates to an essence microcapsule with long-term effectiveness and a preparation method thereof, belonging to the technical filed of microcapsule preparation. The essence microcapsule of the invention is prepared from essence, chitosan, compound emulsifier and other components. The microcapsule greatly reduces the essence loss during the storage and washing processes, improves the aroma retaining effect after washing and has the long-term effectiveness. When being added into washing powder, the essence microcapsule with slow releasing property is used to replace traditional aromatized washing powder, thus significantly retaining the essence no matter in production or in application, and prolonging the aroma retaining time after washing. When aromatized washing powder is produced according to the technology, the process is simple and the operation is simple; and when being added into the washing powder, the essence microcapsule has no toxic or side effect, and can slowlyrelease aroma during washing and prolong the aroma retaining time after washing.