The invention discloses an incoming line automatic bus transfer method in allusion to inner bridge wiring form. The method comprises the following steps: reading the state of two sections of busbar and two incoming lines, judging whether the inner bridge incoming line automatic bus transfer charging and discharging conditions are satisfied, if not, not executing the automatic bus transfer, otherwise, finishing the charging and executing the automatic bus transfer action after the busbar voltage failure, wherein the operation section of the busbar is voltage failure; if the master substation protection action node input corresponding to the section of the busbar is not existent, tripping off an incoming line switch corresponding to the section of the busbar after the time delay, after determining that the incoming line switch is tripped off, switching-on an incoming line switch corresponding to the other section of the busbar and an inner bridge switch after the time delay, and recovering the master substation power supply at the no-voltage side; and if the master substation protection action node input corresponding to the section of the busbar voltage failure is existent, tripping off the incoming line switch corresponding to the section of the busbar after the time delay, after determining that the incoming line switch is tripped off, switching-on the incoming line switch corresponding to the other section of the busbar after the time delay, enabling the master substation corresponding to the other section of the busbar to be electrified, and recovering the power supply of the whole substation through the automatic bus transfer at the low voltage side. The method has both the power grid operating economy and the power distribution reliability.