The present invention discloses a mobile cantilever door-type container inspection system, in the art of radiation scanning imaging inspection technology. The system according to the present invention comprises a moveable scanning apparatus formed by a scanning frame and a remote control device, wherein the scanning frame comprises a radiation source and some detectors, wherein the radiation source or an apparatus cabin wherein the radiation source is disposed is connected with an L-shaped cantilever structure to form a door-type scanning frame, wherein beneath the radiation source or the apparatus cabin wherein the radiation source is disposed are provided with rollers that can reciprocatingly move on rails and are controlled by drive means. The detectors are disposed in a cross beam and a vertical beam of the cantilever structure of the door-type scanning frame. Rays of the radiation source are right in alignment with rows of detectors in the cantilever structure. The container truck to be inspected can pass through the door-like frame formed by the door-type scanning frame. Due to the cantilever structure, the inspection system is advantageous in stable operation, good-quality images, and high reliability.