The invention provides a consumable loading and unloading device. The consumable loading and unloading device comprises feeding wheels, driven wheels, a driving mechanism, a limiting switch, a currentdetection module and an operation control module, wherein the feeding wheels can rotate relative to each other so as to convey the consumable, the driven wheels and the feeding wheels are oppositelyarranged, the driving mechanism is in transmission connection with the feeding wheels, the limiting switch comprises a first microswitch and a second microswitch, the first microswitch and the secondmicroswitch are each provided with an obliquely arranged action reed, the action reed of the first microswitch is triggered before the consumable is in contact with the feeding wheels, the action reedof the second microswitch is triggered after the consumable is loaded successfully, the current detection module is electrically connected with the driving mechanism, and the operation control moduleis electrically connected with the driving mechanism, the first microswitch, the second microswitch and the current detection module. In the process of loading and unloading the consumable, automaticloading is easy to realize, and whether the consumable is loaded completely or whether stop of consumable supply or blockage occurs or not is detected. The invention further provides a detection method of the consumable loading and unloading device and a 3D printer.