Because fire water pump room design in a chemical plant is unreasonable, the flow head of fire pump does not meet the specification requirements, the diameter of fire pipe network is too small, etc., according to the scale and terrain features of the plant, the fire water consumption of each device and tank farm was analyzed and calculated, thereby determining the stable high-pressure fire water supply system was adopted in the fire protection system of the chemical plant, the fire water consumption is 120 L/s and the pressure is 1.0 MPa. At the same time, the fire pump room and fire water supply network were designed according to the code requirements. The renovation scheme of the fire water system reduces the project investment and meets the standard requirements.