Abstract: Digital core technology provides strong technical support for research and engineering applications in the field of geotechnical engineering due to its advantages of high efficiency, accuracy, non-destructiveness and visualization.However, the non-homogeneity of coal rock affects the safety and stability of engineering applications in the field of geotechnical engineering.For this reason, it has become a hot research topic to evaluate the inhomogeneity of coal rock with the help of digital core technology.Based on this, this study constructed a digital core of Ordos bituminous coal with the help of X-ray CT imaging scanning technology, and proposed a calculation method of coal-rock representative units based on TCL writing language, which reduces the computational demand and cost; the quantitative indexes of coal-rock non-homogeneity assessment were proposed, which revealed the complexity of coal-rock pore structure and non-homogeneity.The research results can provide new technical means and theoretical basis for the evaluation of coal rock reservoirs and its related fields.