In view of the problems of breakthrough of injection water and fracture after fracturing in Daqing peripheral oilfields，the high strength plugging agent of controlling channeling path was synthesized by aqueous solution polymerization method，which ensured the effective exploitation of potential placement by subsequent refracturing measures. The formula optimization and performance evaluation of the plugging agent were carried out through laboratory experiments. The optimized formula was 5%— 10% acrylamide，0.1%—0.5% N，N'-methylenebisacrylamide，0.03%—0.1% ammonium persulfate and 20%—25% coupling modified class G oil well cement. The plugging agent was suitable for the formation with the temperature of 40—65℃. The initial viscosity of the plugging agent was 10—15 mPa·s，and the gelling time was controllable within 1 —5 hours，which indicated that the plugging agent had good injectivity. The gelling strength of the plugging agent could be adjusted from 30 N to 300 N. The core plugging rate was greater than 98%，and the breakthrough pressure was more than 20 MPa，exhibiting good plugging performance. The high strength plugging agent was suitable for plugging the water exit of the original fracture and perforation，which ensured the fracture diversion and forming new fractures during the refracturing. At the same time，it was also suitable for plugging the channeling-path formed by natural fracture. It could provide favorable technical support for the effective development of subsequent refracturing measures and realizing water control and oil increment.