A pulsed CuK X-ray source with flux intensity 1018-1019 K X-rays per sr per s has been produced using high current electron beam technique, it has been employed to calibrate the response of the silicon PIN diode detector to pulsed X-ray photon. An absolute X-ray monitor——P10 gas pulse ionization chamber has been used as a standard of the pulsed X-ray flux density, the automatic pulsed charge measuring instrument is controlled and Corrected in real time by a microcomputer. The measured uncertainty of the flux density is ±5%. This chamber is suitable for the range of energy flux rate 4×10-9-2×102 W/cm2 and the range of photon energy 1.5-10 keV. The calibrated accuracy of the detector is ±7.0%. It is found that the pulsed sensitivity of the silicon PIN diode is about 30% higher than the sensitivity calibrated by a steady X-ray beams.