The present invention provides a compact medical X-ray imaging apparatus, which is a portable X-ray imaging apparatus capable of capturing clear X-ray images while maintaining low radiation exposure. The compact medical X-ray imaging apparatus comprises of: a carbon nanostructure triode cold cathode X-ray tube that radiates X-rays an X-ray image sensor that captures an image of X-rays that pass through a patient The first detector that detects the X-ray radiation dose and is positioned between the carbon nanostructure triode cold cathode X-ray tube and the X-ray image sensor, while out of the X-ray irradiation area for the imaging sensor the second detector that detects the X-ray dose and is positioned in the center on one side of the X-ray image sensor frame the third detector that detects the X-ray dose and is positioned on the other side of the X-ray image sensor frame facing to the second detector with the detection surface of the image sensor in between the second and third detector a power supply which supplies a negative and a positive high-voltage pulse to the cathode and anode of the carbon nanostructure triode cold cathode X-ray tube respectively and an X-ray imaging controller which acquires detection data from the first detector, second detector and third detector in addition to the distance from the carbon nanostructure triode cold cathode X-ray tube to the X-ray image sensor, calculates the X-ray radiation dose and amount of decay, determines the optimum X-ray dose for the patient and the voltage of the carbon nanostructure triode cold cathode X-ray tube, controls the pulse number and pulse width of the high-voltage pulse of the carbon nanostructure triode cold cathode X-ray tube, as well as the voltage of the cathode and the anode with feedback control means.
