Reducing-fiber technics of 3D hollow coneshaped fabric braided from big end are researched,including row-directional reducing-fiber technic, annulus-directional reducing-fiber technic, reducing-fiber technic by thinning fiber and combination of these technics. Their effects on fabric structure, operation and mechanisation are analyzed and compared. Reducing-fiber technic by thinning fiber is a kind of special annulus-directional reducing-fiber technic, which may keep structure of fabric complete, make operation simple and make motion of carrier mechanised. However, the unit structure may become complecaled with the change of the dimeter of the fiber bundle.