Abstract: Industrial CT adopts electron accelerator to produce the high energy X-ray bremsstrahlung , and makes use of the principle of different absorption coefficient and scattering coefficient when the X-ray cuts through different materials to check the internal blemish or internal structure of the material. The quantity and the speed of creating image of the industrial CT closely relate to the accelerator's focus, the highest X-ray energy, X-rays dose and dose uniformity. Protecting the electronics circuit of the detector against X-ray relate to the detector's service life. The X-rays measuring results given in this article show that the 9MeV LINAC can satisfie the requirements for checking the material structure and blemish by the high energy industrial CT.