A dummy substrate detection method includes: acquiring a real-time image of a conveying route when a cut substrate enters the conveying route; matching and comparing the acquired real-time image of the conveying route with a first reference image, and determining whether or not there is a dummy substrate on the conveying route according to a comparison result. The first reference image is an image of the conveying route with no dummy substrate. A dummy substrate detector device and a dummy substrate detector system are further provided.