In response to the problems of fully developed micro-fractures in low permeability oil fields, severely heterogeneous reservoir and the fact that traditional profile control are less effective, the self-adaptive weak gel is developed. The static performance, sealing characteristics and displacement efficiency are evaluated through lab tests. The results show that the self-adaptive weak gel has good temperature-resistant and salt-resistant properties. When the salinity of formation water is 41 811.5 mg/L, the weak gel system can gelatinize rapidly in 38 hours, and the gel strength is 28 549 mPa?s under the condition of 70 ℃. Its plugging ratio is 84.08% and the recovery ratio reaches 12.1%. The field experiments of the well S in Ganguyi oilfeild indicate that the preferred path of water breakthrough of water injection well is controlled after profile control and flooding, and the injection pressure rises, at the same time, the water content of well group fell to 69.16% from 78.51%, and daily fluid production rate increases by 135.14%, while the daily oil production rate increases by 237.5%. The deep profile control technology of self-adaptive weak gel has good adaptability in fractured low permeability oil fields. It can enlarge the sweep volume of injected water and enhance oil recovery factor greatly, so it can provide reference for other similar reservoirs to obtain good performance on water control and oil increment.