Abstract: With longer well bore and deeper buried production formation in Jidong Oilfield, the key problem in the later development is interlayer conflict and how to solve it. The technologies of separate layer water injection (SLWI), which using among the Ninth-Five-Plan period, are mainly introduced such as non-fishing technology as setting and testing, separate layer water injection in casing deformation, atc. Several pipe strings of SLWI and their matching tools are also recommend.