An automatic change-over switching device with a mechanical interlocking function comprises a bottom plate, a motor, two execution switches, two manipulators, a mandrel, a controller and a shell; a groove matched with a corresponding poking rod on the mandrel is formed in the lower part of the inside end of each manipulator; the part positioned outside each groove protrudes outwards to form a long-tail-shaped boss; the middles of the two manipulators are respectively arranged at the surfaces of two sides of a motor support in an up-down moving mode; the outside ends of the two manipulators are contacted with an upper handle of each execution switch. The poking rods are enabled not to leave from the manipulators all the time by the long-tail-shaped structures of the manipulators, and the mandrel moves along with the movement of the manipulators, so when the manipulator at one side moves to the upside, the power supply at the corresponding side is switched on, the manipulator at the other side cannot move to the upside to switch the power supply at the corresponding side, the two execution switches are prevented from being switched on at the same time by using the mechanical interlocking of the two manipulators; in addition, an extra mechanical interlocking device does not need to be arranged, so the number of parts and assembly procedures is reduced and the cost is reduced.