At present，polymer microsphere deep profile control and flooding technology is mainly used in high water cut old oilfields to control water and stabilize production，but the effect is not ideal. In order to solve the technical problems of poor matching between ordinary polymer microsphere and pore throat， and limited sealing ability， self-aggregation polymer microspheres NEPU-WMJ and NEPU-NMJ were developed. The physical and chemical properties of the microsphere were evaluated using a high-speed freezing centrifuge and an optical microscope. The compatibility of microspheres with pore throat， profile improvement effect，and oil displacement effect were studied through long sand filling tube displacement and dual tube parallel connection method. The research results indicated that compared to NMKY，NM，WM，and YHM microspheres，the self-aggregation polymer microspheres NEPU-WMJ and NEPU-NMJ exhibited better expansion and long-term stability. After aging at the temperature of 120 ℃ for 4—6 days，the average particle size of NEPU-WMJ increased from 2.57 μm to 44 μm，while the average particle size of NEPU-NMJ increased from 0.08 μm to 89 μm. NEPU-WMJ could maintain stable for about 30 days at the temperature of 120 ℃，while NEPU-NMJ could remain stable for more than 90 days. Self-aggregation polymer microspheres could achieve deep migration in the cores with the permeability of 100×10^-3 —1000×10^-3 μm² with strong ability to improve profile. Under the conditions of temperature of 95 ℃ and permeability difference of 5 and 40，the total oil recovery rate was effectively enhanced by over 24%. In high-temperature environments，the self-aggregation of microspheres could effectively block large pores，activate low-permeability layers，achieve micro profile control and flooding，and significantly improve oil recovery.