With the continuous deepening of water flooding development of low permeability fractured reservoirs in Jiyuan Oilfield, the phenomenon of water channeling is becoming more and more serious, resulting in high water cut and low efficiency production of oil wells. The strong heterogeneity of reservoir caused by the development of channeling fractures is the main reason for water channeling in low permeability fractured reservoirs. The core of water channeling control is to optimize a high-strength profile control system which is easy to inject, has a long validity period and is suitable for fracture profile control. Based on the geological characteristics of Changqing Jiyuan Oilfield, this paper optimizes a gel system suitable for low-permeability fractured reservoirs. After performance evaluation, the field test of Jiyuan Oilfield is applied to obtain better water control and recovery effect, which provides a solution for water channeling control of low-permeability fractured reservoirs. Firstly, through the ratio optimization experiment, the gel system with high gel strength and long validity period is optimized. Secondly, the performance evaluation of the system is carried out, such as temperature and salt resistance, shear resistance, plugging and erosion resistance, crossflow fracture control and sweep, crossflow fracture control in complex media. The results of reservoir applicability experiments show that the optimized long-acting cross-linked gel system has a gel strength of G level under the formation conditions of Jiyuan Oilfield ( salinity 10000 mg / L ~ 50000 mg / L, temperature 60 °C ~ 100 °C ), and the gelling liquid is sheared for 30 min at a shear rate of 3500 rpm. After gelation, the high strength was maintained for 180 days without obvious dehydration, and the plugging rate was > 90 % after scouring ( 10 PV ) experiments on the cores with four kinds of porosity and permeability parameters in Jiyuan Oilfield. Through the crossflow fracture control sweep experiment, it is concluded that the main way to expand the spread of the system is : the injected water bypasses the dominant channel occupied by the gel, turns to the pore to recover the remaining oil, and the recovery rate is increased by 18.4 %, which significantly increases the utilization of the remaining oil in the pore ; through the analysis of channeling fracture control ability in complex media, it is concluded that long-acting cross-linked gel can effectively control the formation of multiple channeling fractures ( the pore recovery rate of 7 fractured cores increases by 31.18 % ) ; the field test of 5 wells in Jiyuan Oilfield has achieved good effect of water control and extraction, which provides system support for water channeling control in low permeability fractured reservoirs.