The invention discloses a belt deviation detecting device for a weighing and feeding machine, comprising a belt position detecting device and a belt position inductive element, wherein the belt position inductive element is arranged on a transporting belt of the weighing and feeding machine, and the belt position detecting device is arranged under the transporting belt and used for detecting a position signal of the belt position inductive element in real time and judging the position of the transporting belt. The belt deviation detecting device for the weighing and feeding machine has simpleand compact structure and convenient installation, can continuously detect the operation position of the transporting belt on line and is beneficial to increasing the work efficiency of personnel andthe utilization rate of devices.