Water control is important for horizontal wells in offshore bottom water reservoir. Conventional water control technology face challenges with difficult annulus sealing and susceptibility to water channeling and sand production. In response to these issues, an innovative integrated sand prevention and water control technology has been developed upon reviewing the advantages and drawbacks of conventional water control techniques. This approach entails the placement of lightweight, hard particles within the annular space between the screen pipe and wellbore to form a dense filling layer. Combined with sand control screens equipped with water control valves, the technology allows for the adjustment of fluid production along the horizontal segments and prevents both sand production and water channeling through the annulus. The sand control and water channeling properties of annular filling layer are evaluated by experimental method. The results show that the channeling flow rate through the annular filling composed of lightweight particles constitutes approximately 4% of the total displacement, effectively serving as an annular sealing mechanism. The sand control performance is similar to that of conventional gravel packing. The application of this process can facilitate the concurrent management of sand prevention and water control. At present, the technology has been applied in wells with high water cut, sand producing wells, and newly drilled horizontal wells with a water cut reduction of 5%~12%. The successful test of this technology provides technical support for the efficient development of offshore bottom water oil fields, and offers reference for sand prevention and water control in reservoirs of the same nature.