As the X oilfield enters the later stage of ultra-high water cut development, the contradictions between layers, interlayers and planes become more and more prominent, the number of sub-injection wells is increasing day by day, the sub-injection intervals are becoming more and more refined, the measurement and commissioning workload is increasing year by year, and the test team’s testing capacity has reached a bottleneck. The use of adjustable constant flow water distribution technology can effectively reduce the test workload, reduce interlayer interference, and ensure the quality of layered water injection. According to the basic principle of constant flow water injection, the geometric model of the fluid domain is established, the internal flow field is simulated, and the force and pressure difference change law of each surface of the valve core are analyzed, so as to design an adjustable constant flow blocker structure, so that a blocker can achieve constant injection of 10–70 m3/d with different flow rates by adjusting the opening of the nozzle. The adjustable constant flow water distribution technology can effectively reduce the cost of water injection, improve the efficiency of measurement and adjustment, and provide new technical support for ensuring the qualified rate of water injection. At present, the starting pressure of the adjustable constant flow blocker is 0.7 MPa, and 58 wells have been tested in the field, with a constant flow error of less than 20%.