Reasonable formation pressure level could not only make the oil well had a higher recovery, but also reduced the difficulty of water injection development. By hydrostatic pressure method, low permeability reservoir determination method, crude oil viscosity determination method and material balance method, the reasonable formation pressure maintenance level was determined. Determination of the reasonable bottom hole flowing pressure water injection was one of the important content of the reasonable injection pressure limit of the system, and was also important basis of water flooding design. The reasonable flow pressure and the reasonable water injection pressure were determined on the basisof determining the reasonable formation pressure maintenance level. The injection-production pressure system was evaluated through the current production status, so as to ensure a higher recovery, and reduce the difficulty of water injection development.