The invention relates to a shale matrix reservoir pore space representation method. On the basis of different types of pores in shale gas reservoir cores and a superposition coupling method, a construction theory and a method which are used for generating digital cores which consider organic pores and inorganic pores at the same time via a mixing method are constructed. According to the digital cores, which consider the organic pores and the inorganic cores at the same time, constructed through a superposition method, geometric topological information of the inorganic pores is retained and space position information of the organic micropores is retained, so that the special pore distribution features of shale rocks can be described at the same time. Geometric topological structure analysis is carried out on the established digital cores, and the fitting degrees between pore radius distribution and coordination numbers and experimental results are relatively good, so that the correctness of the construction method and a numerical value analysis method is verified. According to the method provided by the invention, a basic platform for subsequent structure analysis and microcosmic flow simulation of shale medium pores is established.