A vehicle-carried quick inspection system, comprising: a carrying vehicle, a foldable arm mount provided on the carrying vehicle and configured to be folded onto or within the carrying vehicle in a transportation state and to be unfolded to stride over an inspected vehicle in a working state so as to form an inspection passage through which the inspected vehicle passes during inspection; an X-ray source capable of providing an adjustable radiation dose, provided on the carrying vehicle and configured to radiate X-rays of a desired dose to irradiate the inspected vehicle; a detector provided on the foldable arm mount and configured to be located at a position opposite to the X-ray source and to receive information about X-rays passing through the inspected vehicle in the working state, in which the X-ray source and the detector are arranged on opposite sides of the inspection passage for the inspected vehicle and the inspected vehicle passes through the inspection passage; and a controller configured to control the X-ray source to irradiate different portions of the inspected vehicle with different doses, characterized in that the vehicle-carried quick inspection system further comprises an additional mount and photosensors (151, 152, 153) mounted on the additional mount, the photosensors (151, 152, 153) being configured to transmit signals to the controller when a head portion of the inspected vehicle passes the additional mount in a direction from the head portion to a tail portion of the carrying vehicle, so that the controller actuates the X-ray source to increase radiation dose, thereby the vehicle-carried quick inspection system enters into a high dose inspection state, wherein the additional mount is located at a position downstream of the X-ray source in the direction from the head portion to the tail portion of the carrying vehicle. a carrying vehicle, a foldable arm mount provided on the carrying vehicle and configured to be folded onto or within the carrying vehicle in a transportation state and to be unfolded to stride over an inspected vehicle in a working state so as to form an inspection passage through which the inspected vehicle passes during inspection; an X-ray source capable of providing an adjustable radiation dose, provided on the carrying vehicle and configured to radiate X-rays of a desired dose to irradiate the inspected vehicle; a detector provided on the foldable arm mount and configured to be located at a position opposite to the X-ray source and to receive information about X-rays passing through the inspected vehicle in the working state, in which the X-ray source and the detector are arranged on opposite sides of the inspection passage for the inspected vehicle and the inspected vehicle passes through the inspection passage; and a controller configured to control the X-ray source to irradiate different portions of the inspected vehicle with different doses, characterized in that the vehicle-carried quick inspection system further comprises an additional mount and photosensors (151, 152, 153) mounted on the additional mount, the photosensors (151, 152, 153) being configured to transmit signals to the controller when a head portion of the inspected vehicle passes the additional mount in a direction from the head portion to a tail portion of the carrying vehicle, so that the controller actuates the X-ray source to increase radiation dose, thereby the vehicle-carried quick inspection system enters into a high dose inspection state, wherein the additional mount is located at a position downstream of the X-ray source in the direction from the head portion to the tail portion of the carrying vehicle.