Abstract: Compared with the separate-layer allocation of traditional wireline fishing, the wireless intelligent water regulator greatly improves the separate-layer injection allocation efficiency of offshore large-displacement water injectors. In this industry, however, there is no related selection standard on the nozzle opening of offshore large-displacement wireless intelligent water regulator, so during the field allocation, the nozzle opening can be only selected tentatively according to existing experience. Therefore, there is still some improvement space for the existing separate-layer testing and allocation efficiency. To this end, the pressure loss at water nozzle generated at 15 openings of wireless intelligent water regulator and different flow rates (0-500 m³/d) was simulated by using FLUENT software. As a result, 137 groups of nozzle opening, flow rate and pressure loss data were formed. Then, the simulation data was applied to the allocation operation in 11 water injection intervals of 3 water injectors in Bohai Oilfield. It is shown that the qualification rate of the injection allocation is over 90% while the selection of nozzle opening for 11 water injection intervals is completed in one time, and the single-layer testing and allocation efficiency is 1/2-2/3 higher than that of empirical method, so it can be used to guide the testing and allocation of offshore large-displacement water injectors.