Abstract: In order to further clear the migration feature of crosslinked polymer flooding in the core，analyzing thoroughly its flooding mechanism，taking a natural core from an oilfield as research object，the crosslinked polymer flooding experiment was made using computed tomography（CT）technique，the tracking scanning of the process of crosslinked polymer flooding was used for rebuilding the pore structure of dry core and migration feature images of crosslinked polymer at different displacement time and different locations in the core. Experi?ment results show that CT technique can be used for study of the migration feature of crosslinked polymer，the porosity calculated by the CT is very accurate，the relative error is only 0.93% compared with the measured value; the displacement front of crosslinked polymer in a strong heterogeneity core is still close to the piston，and the injection pressure is increasing for the initial time and then holding steady，indicating that crosslinked polymer can be used for expanding swept volume effectively，and improving microscopic oil displacement efficiency