A micropore throat plugging material was prepared by emulsion polymerization. Its structural characteristics were analyzed by Fourier transform infrared (FT?IR) spectrum analysis, Raman spectrum analysis, and thermogravimetric?differential thermal analysis (TG?DTA). The particle size range of the synthesized product was determined by a laser particle size analyzer. The inhibition performance and plugging performance of the micropore throat plugging material were also investigated. The results show that the thermal decomposition temperature of the synthesized product is 321.0 °C and that its particle size distribution is between 500 nm and 2 250 nm. When the quantity of the micropore throat protection material used is 1.5%, it performs excellently in inhibiting clay hydration. Moreover, the inhibition effect significantly improves when the micropore throat plugging material is compounded with 0.5% sodium chloride. The filter membrane plugging experiment proves that the filter membrane with a pore diameter of 0.45~10.00 μm can be effectively plugged by the proposed material, and the plugging time is up to 35.43 min when the plugging quantity is 1.5%. After aging at 120 °C for 16 h, the high temperature and high pressure filtration loss is 10.0 mL when the amount of the micropore throat plugging material added is 1.5%.