The invention discloses a well pressure control separate-layer packing water injection string which comprises a string body. The string body is arranged in a casing, pressure transmission control hydraulic-control packers are arranged between the outer wall of the string body and the inner wall of the casing, and a pressure transmission downhole hydraulic-control packer unsetting control device and a pressure transmission downhole hydraulic-control packer setting control device which are connected with the pressure transmission control hydraulic-control packers are mounted on the string body. The pressure transmission downhole hydraulic-control packer unsetting control device is positioned above the pressure transmission control hydraulic-control packer on the uppermost layer. The pressure transmission downhole hydraulic-control packer setting control device is positioned below the pressure transmission control hydraulic-control packer on the lowermost layer. The well pressure control separate-layer packing water injection string has the advantage that pressure difference of fluid in the oil pipe casing in the well pressure control separate-layer packing water injection string can be adjusted under the condition that internal pressures of hydraulic-control pipelines do not need to be controlled by the ground, and accordingly the hydraulic-control packers can be quickly set and unset under the control.