Abstract: An experimental system and a numerical model are developed, which use a continuous X-ray source to determine the X-ray direct drive response of strip line in vacuum. The experimental system includes a vacuum cavity, a vacuum group and an electrometer, and the numerical model is a 1-D strip line model which is able to describe the gaps between cables conductor and dielectric and the conductivity in the dielectric induced by X-ray. The continuous X-ray environment parameters, such as the X-ray spectrum, flux and so on, are obtained by using MCNP Monte Carlo program. Two strip line models are tested and the experimental results are compared with responses calculated using the numerical model above. It indicates that the X-ray direct drive current waveforms are similar and their amplitudes are approximate, if the gaps hypothesis is permitted which is destined to exist in a real strip line. Therefore, the numerical model used to describe cables response under continuous X-ray environment is reasonable to some extent.