Abstract: Aiming at solving the problem of rapid coning of bottom water during the development by horizontal wells in the sandstone bottom water reservoir of offshore oilfields, a life-long water control completion technology in offshore oilfields was studied based on the analysis of the advantages and disadvantages of inflow control device (ICD) and autonomousinflow control device (AICD). The technology combined the advantages of ICD and AICD. During the early production period, the high permeability section was constrained to balance the liquid supply profile in the horizontal section of the horizontal wells. In the later periods, the "autonomous flow rate control" was used to constrain the liquid flow of the horizontal high water content section, which could slow down the increase in water cut by autonomous water control. The technology was tested on-site in Well W1 in Reservoir H of Oilfield X. By comparing with production wells in the same reservoir, it is shown that the life-long water control completion technology can restrain the increase of water cut in the development by horizontal wells and is worthy of expanding the test scale.