Profile control technology in offshore oil fields is an effective treatment method for reservoirs with high water cut. Polymer gel has a high plugging strength but poor injectivity，while polymer microsphere has a good injection performance，but its plugging strength is greatly affected by concentration. To overcome the above problems，the AM/AA polymers were used as the core layer of the polymer microspheres，and the decomposable crosslinking agent PEGDA and the functional monomers AM and AA were coated to form the shell layer of the polymer microspheres，and then the organic crosslinking agent SZ was modified in the polymer shell layer to obtain a coated sustained-release profile control system using the inverse emulsion polymerization method. The factors affecting the viscosity increasing performance of the system was investigated，and its release process of viscosity components was also systematically characterized by using microscopy，transmission electron microscopy，nuclear magnetic resonance spectroscopy and Fourier transform infrared testing methods. Besides，core flooding experiments were conducted to characterize its injection performance and sealing performance in the target block. The results indicated that the system initially existed in a micrometer sized spherical state，and it swelled and released viscosity increasing components within 1—7 d. The process of releasing viscosity increasing components was influenced by several factors such as the amount of monomer and crosslinking agent，temperature，mineralization degree and shear rate. When the acrylic acid amount was 40%，the system viscosity was optimal. By adjusting the amount of crosslinking agent PEGDA（0.005%—0.300%），controllable release of the viscosity-increasing component could be achieved，2% highly active crosslinker SZ demonstrated both optimal gelation time and viscosity characteristics. The resistance coefficient of the system in the target high-permeability reservoir was ＜5，and the residual resistance coefficients at the injection end，middle，deep part reached 18，8，5，respectively，indicating good injection capacity and deep plugging capability.