Abstract: There are problems of small drift diameter, less separate injection series, bothering pulling test in the course of mechanical sand control and hollow separate injection. To solve these, the techniques of large bore separate layer sand control and slim hole separate flooding were implemented. The technology of separate layer sand control and eccentric flooding was developed in 177.8 mm casing injection wells. Separate layers could reach as many as 3 sections and bore size of sand control screen came to 108 mm while injection string diameter was 46 mm. The technology can meet the needs of sealing test, quantitative water distribution, pulling inspection and so on. It provides a technical idea for reliable sand control, more separate injection series and simple pulling test.