The invention discloses an overweight detection device. The overweight detection device comprises a bearing plate, an electromagnetic distance measurement device used for measuring the deformation quantity of an elastic extension component, the elastic extension component, a lifting chain rod and a spring seat, wherein the electromagnetic distance measurement device comprises an electromagnetic distance inductor and an induced magnet, the induced magnet is fixed on the bearing plate, the adjustable electromagnetic distance inductor is installed on an effective path corresponding to the induced magnet in position, and the lifting chain rod perpendicularly penetrates through a bearing box plate and is connected with the spring seat. When weight on the bearing plate increases, the elastic extension component is stretched, the overweight detection device accurately measures the deformation quantity based on the principle that the elastic extension component deforms when being stressed and by utilizing the electromagnetic distance inductor, further judges whether the situation of overweight occurs, and effectively avoids accidents caused by overweight.