an X-ray generator;

a stand placed on a horizontal plane;

a flat panel detector provided on the stand; and

a support mechanism comprising:

a support tube;

a transmission component for driving the X-ray generator to move towards or away from the support tube;

a drive component for driving the X-ray generator to rotate; and

a support pole slidingly provided in the support tube, and

wherein the X-ray generator is detachably provided on the support pole; and

the transmission component comprises:

a transmission motor provided in the support pole;

a transmission gear; and

a transmission rack provided on an inner wall of support tube,

wherein the transmission motor is connected with the transmission gear, the transmission rack is provided in a length direction of the support tube, the transmission gear is engaged with the transmission rack to drive the support pole to slide in the support tube, one end of the support pole far from the support tube is connected with a mounting platform for mounting the X-ray generator, and the mounting platform is detachably connected with the support tube.