Abstract: In view of the limitations of conventional polymer flooding, such as serious viscosity loss due to mechanical degradation during injection and weak flooding profile control ability in deep reservoirs, a novel targeted viscosity-enhancing oil displacement agent (TVP) was developed. It is formulated by encapsulating conventional polymers within microcapsule shells using inverse emulsion polymerization and interfacial in-situ polymerization technologies, inspired by microencapsulation techniques from other application fields. The release process of TVP was characterized by microscopic methods, and the influencing factors of TVP sustained-release, anti-shear performance, resistance coefficient before and after sustained-release, and oil displacement effect were studied. The results show that TVP is spherical with an average particle diameter of 600～800 nm before sustained release. The microcapsule shell can release polymers under high temperatures or high pH conditions. After release, the polymer will dissolve in water, forming a network structure, which can increase the aqueous phase viscosity to approximately 30 mPa·s at a mass concentration of 5000 mg/L. Protected by microcapsule shell, TVP has strong mechanical shear resistance, with only 3.3% viscosity loss after shearing. Before TVP sustained release, the resistance coefficient of core flooding is only about 3.0, indicating favorable injectivity. After sustained release, the resistance coefficient of core flooding rises to 36.88, achieving an incremental oil recovery of 26.7 percentage points, which demonstrates favorable sweep efficiency and oil displacement performance. Field trials of TVP were carried out, and the results showed that the average injection pressure of three water injectors increased by 6.4 MPa, the dynamic fluid level of two producers increased, the water cut decreased, and the daily oil production increased by 4.4 t, indicating preliminary favorable effectiveness of polymer injection. The results also show that TVP, as a new oil displacement agent, has the potential to significantly improve crude oil recovery in tertiary oil recovery.