A variety of analytical techniques is indispensable for the development of earth sciences. In particular, with the great advances in modern technology, more advanced modern analytical testing methods play a role in earth sciences, industrial X CT (X ray Computed Tomography) is one of important modern test technology. It could intuitive display geological rock samples interior structure, which demonstrates two dimensional or three dimensional information, we could use two dimensional images to take full digital processing and three dimensional visualization analysis. Based on the principles and methods of industrial computed tomography (CT) technology, studying pore structure of Fujian Kuiqi geode granite KQ 6 sample in South China metallogenic belt, acquiring two dimensional CT image sequences of the sample, by means of digital image processing analysis tools, finally we obtained the sample porosity and pore size statistics distribution, which the measured value of porosity is 8.14%, and pore size is 0.4~2 mm; Thus, carrying out three dimensional visualization study on pore structure of geological samples to obtain topological graph of porous connection of the samples, can intuitively demonstrate interior pore connectivity of samples, which is vital for depiction on the interior structure characteristics of geological samples and ore forming fluid.