In order to evaluate the effectiveness of continuous packer water control technology in offshore sandstone reservoirs and fractured reservoirs, the mechanism and experimental study of continuous packer water control technology were conducted. Using continuous packer filling to the wellbore and well completion string annulus and the formation cracks, replace the axial packer, the packer cracks choke, the flow control filter can limit the flow radially according to the change of the viscosity of different fluids, has realized the oil well fine segmentation, advanced flow control, balancing oil wells productivity contribution paragraphs, uniform oil water interface and the purpose of oil well water control. Combined with the characteristics of reservoir properties and continuous packer water control technology, 12 wells of continuous packer field application have been carried out in offshore oilfield. Through the comparison of production data before and after the implementation of continuous packer technology, the results show that the success rate of continuous packer technology is 100% ,the success rate of oil increase and precipitation is higher than 90% , the cumulative oil increase is more than 10 × 10⁴ m³ , the precipitation is more than 10 × 10⁶ m³ , the input output ratio is more than 1:10, and the overall effect of water control and oil increase is good. The results of this study can be used for reference in the future application of the technology in off shore oil field.