After a long time of water injection development in M oilfield, some water injection wells have the phenomenon of water injection pressure rising, and after conventional acidizing and plug removal measures, the effective period is quite short. Therefore, it is necessary to study more efficient and reasonable plug removal and injection increase measures to meet the needs of water injection development in this oilfield. The results show that the injected water and formation water of M oilfield both contain more scale forming ions, which are easy to form inorganic scale under the condition of reservoir temperature and pressure, and block the reservoir. In addition, the suspended matter content and oil content in the injected water are high, which is easy to cause the solid particle plugging and crude oil emulsion plugging. Core displacement experiment results show that the damage rate of the natural core permeability caused by the mixed scaling of injection water and formation water can reach more than 45% , the damage rate of the core permeability caused by the solid particles in the injection water can reach more than 35% , and the damage rate of the core permeability caused by the emulsification of crude oil in the injection water can reach more than 30% . The research results show that the high-efficiency compound solution can effectively remove the plugging damage of the natural core in the reservoir section of M oilfield, and achieve a good effect of reducing pressure and increasing injection.