In order to better exert the effect of controlling water and stabilizing oil for nano/micron-sized polymer particles dispersion system in low permeability reservoir，viscosity properties，rheological properties and plugging performances of the system were studied，and the influence of injection pressure，permeability，hydration time，mass concentration and injection rate on plugging performances in cores were investigated. The test results show that the polymer particles dispersion system has a small viscosity which is a pseudo plastic fluid with shear thinning. Meanwhile，it has good injection characteristics and plugging effect. When polymer particles dispersion system is injected into cores，its injection pressure has the trend of fluctuation. With a certain hydration time，mass concentration and injection rate，the interval where the ratio of average particle diameter to average throat diameter is less than 0.16 is the weak plugging region，and where the ratio of average particle diameter to average throat diameter is more than 0.32 is the strong plugging region，and where the ratio is between 0.16 and 0.32 is the medium plugging region. Moreover，the area of the weak plugging region increases and the strong region decreases with increasing hydration time. With a certain hydration time，injection rate and core permeability，the interval where particle concentration is less than 1.0 g/L is the weak plugging region and where particle concentration is more than 2.0 g/L is the strong plugging region. With a certain hydration time，mass concentration and core permeability，the interval where injection rate is less than 0.1 mL/min is the weak plugging region and where injection rate is more than 0.5 mL/min is the strong plugging region.