A grounded-wire-removing omission-preventing alarm comprises a grounded wire conductive terminal, a PVC element box, a moving contact and a static contact. An indication lamp is mounted to one end of the PVC element box, a wireless signal sensor, a caution loudspeaker and a cell for supplying power are disposed in the PVC element box. An aluminum alloy conductive end plate is fixed in a hook of the grounded wire conductive terminal, a conductive end plate clamping spring is disposed at the outside of the conductive end plate, a cantilever end of the conductive end plate is fixedly connected with the moving contact, and the opposite side of the moving contact is provided with the static contact with an adjustable height. When the grounded wire conductive terminal is mounted to a bus, the moving contact opens along with the conductive terminal to close with the static contact, a loop of a device is conducted, and the caution loudspeaker and the indication lamp of the PVC element box are triggered, so a usage state of a ground wire can be reported at set intervals to caution a worker to be careful. The grounded-wire-removing omission-preventing alarm has functions of prompting through voice and light, safety risks of switching on with a grounded wire can be eradicated effectively, and a safety defense line can be added for safety operation of an electrical network.