Synthesizing core, outcrop, drilling data, the sedimentary environment was reconstructed. The petrography analysis, reservoir space category summary, diagenesis recovery and controlling factors of the reservoir analysis were conducted. The tight sandstone reservoir with dual medium in Toutunhe formation fractures of Sikeshu sag has the characteristics of “three low one weak” of low component maturity, low shale content and lower cement content. The pore type is mainly composed of remaining intergranular pores and a few intragranular pores and fissure types mainly consist of bedding fissures and diagenetic fissure. The principal elements controlling the tight sandstone reservoir property of in Toutunhe formation fractures of Sikeshu sag are depositional environment, burial process, compaction and tectonism. The tight sandstone reservoir with braided river delta front subfacies that developed in the Gaoquan anticline and West Lake anticline has favorable prospect for exploration. The coarse sandstones with a small amount of plastic grain content possesses better reservoir quality. The reservoir is mainly controlled by compaction. Denudation pore increasing and cementation hole reduction is limited. Fissures improve reservoir properties effectively.