X-rays have the characteristics of high single photon energy, high frequency, and strong penetrating ability, are widely used in space communication, radiation imaging, medical diagnosis, non-destructive testing, and other fields. The development of X-rays has had a positive impact on broadening the use of the electromagnetic spectrum. As the core component of the X-ray application, high modulation rate, low power consumption, and excellent performance X-ray generators have been a hot research topic for decades. In this paper, a light-controlled pulsed X-ray source is modeled by simulation software. We perform simulation calculations and summary analysis on the effects of cathode structure, focus structure height, and metal anode voltage on the focal spot size, electron transit-time, and transit-time spread. At an operating voltage of 30KV, if the photocathode is 42mm in diameter, the focal spot diameter is about 1.5mm, the electron transit-time is 3.75ns, and the transit-time spread is 895ps when the focusing structure height is 6mm. And if the diameter of the photocathode is 12mm, the focal spot diameter is the smallest when the focusing pole height is 9mm, which is about 0.7mm, as for the time characteristics, the electron transit-time is 4.1ns, and the transit-time spread is 242ps. The results suggest that the light-controlled pulsed X-ray source is expected to be the next-generation source with easy modulation and short X-ray pulse properties. © COPYRIGHT SPIE. Downloading of the abstract is permitted for personal use only.