Abstract: In view of the limitations of conventional polymer flooding, such as serious viscosity loss due to mechanical degradation during injection process and weak ability of deep reservoir flooding, a novel targeted viscous-increasing oil displacement agent (TVP) was developed by using reverse-phase emulsion polymerization and interfacial in-situ polymerization technology to cover conventional polymer in microcapsule shell by referring to microcapsule technology involved in medicine, textile, coating and other fields. The process of TVP sustained release was characterized by microscopic means, and the influencing factors of TVP sustained release, mechanical shear resistance, resistance coefficient before and after sustained release and oil displacement effect were studied. The results show that TVP is spherical with an average particle size of 600～800 nm before sustained release. The microcapsule shell can release polymer at both high temperature and high pH value, and the polymer dissolves in water to form a spatial network structure after release. At a mass concentration of 5000 mg/L, TVP can increase the aqueous phase viscosity to about 30 mPa·s. Under the protection of the microcapsule shell, TVP has strong mechanical shear resistance, and the viscosity loss rate after shear is only 3.3%. Before TVP sustained release, the resistance coefficient of injected core is only about 3.0, and the injection performance is good. After TVP sustained release, the resistance coefficient of injected core is increased to 36.88, and the internal enhanced recovery rate can reach 26.7%, which has good deep reservoir spreading and displacement ability. In the field test, the average pressure of the three injection Wells increased by 6.4 MPa, the dynamic fluid level of the two Wells increased, the water cut decreased, and the daily oil increase was 4.4 t. As a new oil displacement agent, TVP has the potential to significantly improve oil recovery in tertiary oil recovery.