Abstract: A method, based on micro focus cone beam X-ray computed tomography, for measuring lower-range density of energy material cylinders was introduced. The linear relationship between energy material volume density and volume CT gray value was obtained through synchronized detection and VCT gray value calculating. Each specimens CT density was calculated from VCT gray value based on the whole specimens drainage density. The result showed that the self-comparison method could simplify the measuring local-density uniformity of energy material, and the relative error between drainage density and VCT density of each specimen was less than 0.1%.