The invention relates to a microcapsule containing functionalized graphene in a capsule wall and a preparation method of the microcapsule. In the microcapsule, a crosslinked membrane of sulfhydrylized graphene obtained by modifying a compound which simultaneously contains sulfhydryl and amino or bio-molecules is used as the capsule wall, and an oil phase which is loaded with hydrophobic drugs is used as a core material. The preparation method is achieved by ultrasonically radiating a water solution containing the sulfhydrylized graphene and the oil phase which is loaded with the hydrophobic drugs so as to obtain the microcapsule which contains the functionalized graphene in the capsule wall. The microcapsule disclosed by the invention is capable of achieving the controlled release of the drugs on the basis of the reducing responsiveness of a disulfide bond; and the preparation method is simple to operate, efficient and rapid and high in drug loading capacity, and the preparation method is not easy to introduce impurities, widely applicable to the cladding of the hydrophobic drugs and excellent in application prospect.