To improve the reliability of distributed feeder automation fault location, a distribution network switch group model is established. Based on switch group model, the failure process due to switch rejecting is researched. The fault handing principles are proposed based on logic operations. By supplementing the principle of single-shot reclosing, the extension of fault isolation scope is avoided effectively when the switch rejects to break. Through analyzing the switch rejecting to close, a secondary reclosing processing method is proposed to avoid fault isolation extending. The fault handling process is researched in three cases of communication failure of the adjacent switch. A uniform failure determination method is given. Incidental interference and permanent failure are discussed in switch protection signal failure. The research shows that incidental interference has no effect on fault isolation, while permanent failure will expand the scope of fault isolation. The results of many cases study show the feasibility and effectiveness of the proposed approaches.