The monitoring device of the disclosure includes a carrying unit having at least one carrying area for carrying a monitored object, at least part of the carrying area is provided with a corresponding image capturing unit and a corresponding optical path adjusting unit; the image capturing unit captures a monitoring image of the carrying area, each image capturing unit has a preset field of view, each image capturing unit forms the monitoring image according to light incident from the field of view; at least part of the carrying area is an extension area, the extension area is positioned outside the field of view of the image capturing unit; the optical path adjusting unit enables the light emitted from the extension area of the carrying area corresponding thereto to enter the image capturing unit from the field of view of the image capturing unit corresponding to the carrying area.