Polymer flooding is a mature and important technology to enhance oil recovery. Due to the injection process and high-speed shear in the process of polymer preparation and injection，the viscosity loss of polymer is serious，the mobility ratio is reduced，the spread capacity is reduced，and the oil recovery is affected. In order to solve the problem of polymer shear resistance， the dissolution，shear，seepage and oil displacement properties of microencapsulated emulsion polymer with polyurethane as shell material were studied. The study showed that the microencapsulated polymer presented the morphology of capsule microspheres， and the average particle size of the microspheres was about 500 nm. The microencapsulated polymer began to show signs of shell breaking at 3 h，during the continuous stirring process in water，the shell was quickly broken after 6 h，and the full shell breaking time was about 13 h. In the process of seepage in porous media，when the microencapsulated polymer migrated to 1.33 m（10.6 h）， the shell began to be broken；the shell rapidly was broken after migrated to 2 m（16 h），and the shell was fully broken after migrated 3.33 m（26.6 h），the shell was fully broken and the polymer was released. The molecular chains of the polymer aggregated with each other in the aqueous solution，showing a relatively dense network structure and obvious viscosity increasing characteristics. In homogeneous and heterogeneous cores，the oil recovery of microencapsulated emulsion polymer was higher than that of HPAM by more than 6 percentage points. The viscosity loss rate of the microencapsulated emulsion polymer after high-speed mechanical shear was only 5%，so high resistance coefficient and residual resistance coefficient could be established in the porous medium，which could realize the expansion sweep and enhancement of oil recovery.