The matching relationship between the size of SMG-mm crosslinked polymer microspheres and the pore size of the nuclear membrane was studied by filtration experiments. The results show that the plugging effect of the microspheres with different pore sizes is very different, and there is a membrane pore size matched with the size of the microspheres. When the concentration and membrane pore size are the same, the pressure has a significant effect on the filtration results. In a certain concentration range, with the increase of concentration of microspheres dispersed system and filtration pressure, plugging effect is better. While when the concentration exceeds the optimum value, the performance of the plugging effect is more terrible; SEM observation results show that the effective plugging can be formed when the diameter of the microspheres and the pore size of the membrane are the best match.