Based on the sedimentary and lithofacies palaeogeographic characteristics of the target strata of shale gas in Dacheng-Wen’an area, and characteristics of cap formation, reservoir burial, thickness, organic matter type, abundance, etc., the geological conditions of shale gas formation in Dacheng-Wen'an area were evaluated based on the organic-rich shale rocks of the Shanxi and Taiyuan formations as the research object. The results showed that a set of dark mud shale formations with good shale gas reservoir conditions was developed in the Dacheng-Wen'an area, with an average TOC value of 2.60% and Ro 0.7%～1.0%, and both TOC and Ro were in favorable gas stage, which provided a reliable geological basis for shale gas resource exploration and development.