An anti dumping switch includes a circular and hollow housing, a bottom surface connected to the housing, a first switch end, a second switch end, a bush, and two balls, the housing and the bottom surface cooperatively defining a accommodating space, the first switch end and the second switch end both extending into the accommodating space through the bottom surface and fixed in the bottom surface, the balls being received in the accommodating space. When the anti dumping switch is flat the balls connecting the first switch end and when the anti dumping switch is dumped the balls disengage with the first switch end or the second switch end, wherein the first switch end is disposed at substantially a center of the bottom surface, the second switch end being disposed adjacent to the housing, the bush being received in the accommodating space and cycling the housing from inside and connecting the second switch end, the bush including a slope surface disposed adjacent to the bottom surface that make the balls contact the first switch end or the second switch end.