Abstract: Segregated fracturing technology of horizontal well have a strong pertinence to difficult-to-produce reserves in west of Sichuan.Through the optimization of fractures number,half-length of fracture,length combination,etc,we get the optimization fracturing parameter of horizontal wells in Shaximiao formation of Xinchang gas field and developed made in China packer combination suitable in casing well,which applied to carry on segregated fracturing with packers.This technology is applied successfully in XS21 and in-crease production.