In order to study the key technology of early diagnosis of breast cancer in medical system, an X-ray imaging test bench for punctual X-ray source is developed. The test bench consists of a pulsed power trigger and a pulsed X-ray tube. The pulsed flip-flop power supply consists of a Marx generator, a spark gap switch, a capacitive voltage divider and an output section. Pulsed X-ray tube utilizes the mechanism of cold cathode reflection bombarding anode target to emit X-ray. This method can effectively improve the repetition rate of radiated X-ray point source position, and adjust the material and distance of cathode and anode according to different driving voltage to ensure the output of X-ray photon energy in the pulse X-ray tube. In the case of more than 15 keV of X-ray photon energy, the size of the X-ray point source can reach the design index of less than 100 μm. Simplorer simulation results show that when the impedance of the pulsed X-ray tube is 57 Ω, the output voltage of the pulse trigger is 169 kV, the rise time is less than 10 ns, and the pulse width is less than 100 ns.