Abstract: Geoscan series was established by means of X-ray intensity adjustment and scanning way update based on the micro X-ray computed tomography (CT). Sample room was converted to a flat type to extend scanning area, which realized the 3D scanning imaging of full diameter cores. Test results showed that the 3D parameters of full diameter, including core section structure, bedding structure, heterogeneous configuration and hole-seam distribution, could be used to get clear 3D images, which was difficult to describe in the past. Through the full diameter scanning of drilling cores, we analyzed the mineral content, hydrocarbon migration pathway and aperture ductility in a more extensive depth. The digital processing images of reservoir property parameters can reflect the effectiveness of hydrocarbon accumulation and the reservoir distribution rules. This technology provides a 3D visual image for the porosity and permeability of reservoir rocks and a qualitative evaluation of reservoir quality, which may optimize hydrocarbon explorations.