The invention relates to an interlock switch loop used for an electric vehicle. The interlock switch loop comprises a battery manager, a vehicle-mounted charger, a ground charging pile and an interlock relay, wherein the battery manager is separately connected with a negative main contactor, a positive main contactor, a pre-charging relay and a charging relay; and a drive motor, an electric air conditioner and other high-voltage loads are connected on the positive main contactor and the negative main contactor. The interlock switch loop has the beneficial effects that by virtue of an innovative structure design of the charging-discharging interlock circuit system, power supply is guaranteed to be not provided for the whole vehicle power system, so that illegal start of vehicles in charging is prevented; high-voltage electric shock hidden danger is completely eliminated, and the safety of a driver and passengers is improved; before starting of the whole vehicle or during operation of the whole vehicle, when any connector assembly of a high-voltage power distribution box is loosened or drops, a system timely reports faults and takes measures to limit or prevent the vehicle from operating, so that the driver is reminded of checking and repairing the vehicle, and therefore, the system safety performance of the whole vehicle is further improved.