The morphology,swelling performance,temperature resistance and plugging performance of a novel double⁃crosslinked structure temperature⁃resistant polymer microsphere were studied by scanning electron microscopy,laser particle size analyzer and microporous membrane filtration experiments.The results show that the original shape of the microspheres is spherical with smooth surface,and the particle size is mainly distributed between 200 nm and 300 nm.The microspheres swell 5 times after swelling for 30 days at 140 ℃ in an aqueous solution with a salinity of 10 000 mg/L.With the swelling time,swelling temperature and microsphere concentration increasing,the plugging characteristics of the microspheres to the microporous membrane is gradually enhanced.The microspheres with the swelling for 30 d at 140 ℃ have the best plugging effect;with the increase of the pore size of the membrane, the microsphere plugging effect is weakened.The microspheres still have good plugging performance after swelling at 140 ℃ for 30 d,indicating that the microspheres have good temperature resistance.