To ascertain the pore structure characteristics and methane adsorption capacity of organic-rich shale in the Lower Silurian Longmaxi Formation of Zhaotong Demonstration Area，southern Sichuan Basin，the low-temperature nitrogen adsorption experiments and high-temperature methane adsorption experiments were designed to obtain parameters of pore structure in organic-rich shale. And then isothermal adsorption line was fitted by using the revised Langmuir-Freundlich model to evaluate the methane adsorption of shale samples. At last，the effect of microscopic pore structure on the methane adsorption capacity of the shale was discussed. The results show that the ink-bottle-like and slit-like pores are the main pore types of the organic-rich shale in the study area. The specific surface area ranges from 9.429 to 27.742 m2/g；the pore volume ranges from 0.011 to 0.02 cm3/g；the average pore diameter ranges from 8.546 to 10.982 nm，and the fractal dimension ranges from 2.552 2 to 2.725 5. The Langmuir-Freundlich（L-F）model was used to fit the experimental data of methane adsorption of shale samples at 30 ℃，and the Langmuir volume ranges from 1.397 32 to 4.076 61 m3/t，indicating that the methane adsorption capacity of different shale samples varies obviously. With the increase of total organic carbon content，the number of organic matter pores in organic-rich shale samples increases，and the specific surface area increases too，which provides more positions for methane adsorption and thus enhances the methane adsorption capacity. On the other hand，with the increase of fractal dimension，the pore surface of the shale becomes more irregular，and thus the pore diameter of the shale becomes smaller. As a result，the adsorption potential between pore walls increases and the methane adsorption capacity of shale increases. Clay minerals in the organic-rich shale have little contribution to the adsorption capacity.