In recent years, organic rich shale microfractures have attracted much attention due to their potential significant impact on hydrocarbon migration and recovery during unconventional shale oil and gas exploration and development, as well as underground in-situ transformation of oil shale (and medium low maturity shale oil). However, many issues regarding the evolution patterns of microcrack networks, the opening and closing times of microcracks, and the storage and migration of fluids within them are still unclear. In response to this scientific issue, Associate Professor Shao Deyong from our department led the team in charge of the extension of the Ordos Basin₃ Taking organic rich shale as an example (Figure 1), the thermal evolution process of the micro fracture network caused by hydrocarbon generation overpressure was restored and explored through simulation experiments of high-temperature and high-pressure golden tube system of rock small columns, combined with scanning electron microscopy and micro nano CT technology.