The utility model discloses a stand -by power supply of electric substation control box, switch and at least three routes stand -by power supply's interface is hauled oneself willingly into to two atleast dual supplies in including the box and locating the box, the dual supply is hauled oneself willingly into the switch and is included that the dual supply hauls oneself willingly into switch A and dual supply and haul oneself willingly into switch B, and the switch commonly used end that switch A was hauled oneself willingly into to first via stand -by power supply's interface and dual supplylinks to each other, and the sharing end that switch B was hauled oneself willingly into to switch A was hauled oneself willingly into to the dual supply standby switch end and dual supply links to each other, the switch commonly used end that switch B was hauled oneself willingly into to second way stand -by power supply's interface and dual supply links to each other, and the standby switch endthat switch B was hauled oneself willingly into to the dual supply links to each other with third way stand -by power supply's interface. The utility model discloses a stand -by power supply controlbox is set up, the automatic switch -over of the normal power supply and stand -by power supply power supply can be carried out to three routes stand -by power supply's automatic switch -over can be carried out, emergent on -the -spot respond has effectively been improved quick.