Abstract: Aiming at the problems of rapid pressure rise and frequent blockage of injection wells in Bohai oilfield, through the analysis of injection water quality and solid phase particle size, combined with physical model experiment, the factors and plugging regularity of injection wells in low permeability reservoirs were studied in details. The experimental results show that the reservoir blockages are mainly caused by solid particles injected into water(average particle size > 2μm). The permeability of low permeability and ultra-low permeability reservoir cores decreases with the increase of injection amount, the increase of solid particle content and average particle size, and the damage degree increases. The damage of solid particles to ultra-low permeability cores is greater than that of low permeability cores.