Single-phase reclosing technique can enhance the service reliability，but when reclosing to permanent faults， it brings about another surges to power systems. Hence it is necessary to study the influence of reclosing sequence on transient stability margin. In this paper， Taking an single phase ground fault on Anshun-Tianshengtiao 500 kV transmission line of Southern China Power Grid with 2005 year’s flood season-large power flow as an example， the influence of single-phase reclosing time sequence on transient stability margin is simulated by FASTEST software without effectively distinguishing the transient and permanent fault. The simulation results indicate that reclosing firstly by using non-voltage detecting at non-fault terminal instead of at two terminals in turn can enhance the transient angle， voltage and frequency stability margin greatly， and improve the working condition of breaker to cut off short-circuit current twice. Based on this， an online reclosing method combined with fault location algorithm to modify single-phase reclosing sequence is proposed to enhance transient stability and decrease the surge when reclosing to permanent fault.