The J oilfield in Bohai has experienced long-term chemical flooding，and the low permeability part of the injected well reservoir is seriously blocked. The effect of conventional plugging removal measures is poor. It is urgent to develop new plugging remover and plugging removal process. Therefore，taking the backflow blockage of polymer flooding wells in the target reservoir of Bohai oilfield as the research object，the construction，performance evaluation and process research of plugging remover for chemical flooding injection well were carried out. The results showed that the backflow blockage of chemical flooding wells in the target oilfield was composed of 87.77% water，3.83% crude oil，2.76% polymer and 5.64% inorganic scale. The inorganic scale mainly included 59.1% SiO₂，25.9% CaCO₃ and 11.4% MgCO₃，meanwhile contained a small amount of BaCO₃，SrCO₃，BaSO₄， SrSO₄ and Fe₂O₃. According to the composition of blockage，a new type of plugging remover composed of organic solvent， depolymerization agent and scale-dissolving agent was constructed. The preferred organic solvent was a mixture of toluene and n-pentanol（mass ratio of 9∶1—7∶3），the depolymerization agent was 0.5%—1.0% ammonium persulfate，and then the scale-dissolving agent was 5.46% scale-dissolving agent 1（α-cyclodextrin inclusion and β-cyclodextrin inclusion）and 0.54% citric acid. The scale-dissolving effect of three types of plugging remover in turn was better than that of compound dosing method. According to the dosing sequence of depolymerization agent，organic solvent and scale-dissolving agent （mass ratio of 1∶2∶3），the scale-dissolving rate of the blockage was 98.1%. The results of core plugging removal experiments showed that the new plugging remover had a plugging removal rate of more than 80% for inorganic mixed scale and polymer plugging. Compared with single plugging removal operation，the combined operation of inorganic gel profile control and plugging removal had dual effects of “plugging”and“dredging”. The recovery rate was increased by 6.9 percentage points.