Abstract: Single-phase disconnection fault is a kind of fault with strong concealment and easy to be ignored in indirect neutral-point grounding system. Taking several single-phase disconnection faults at the power supply side of a 35 kV indirect neutral-point grounding system in Zhejiang Province as example, the causes are analyzed on such faults in principle, and suggestions on rapid identification and prevention of single-phase disconnection faults are put forward based on the analysis of abnormal voltage at power and load side in those failure cases,which offers reference for dispatch and maintenance personnel to accurately identify, timely settle and efficiently prevent such faults.