The cast thin section analysis, high-pressure mercury, constant-speed mercury porosimetry, steady seepage, X-ray diffraction and acoustic emission of rocks under triaxial compression methods are used to experimentally investigate the reservoir space and physical property parameters of the Chang 81 tight sandstone reservoir in the Zhenbei Area. The results show that the reservoir space is dominated by intergranular pore and intergranular dissolution pore, followed by intragranular dissolution pore (feldspar dissolved pore and lithic dissolved pore), and only few areas exhibit intercrystalline pore. Three types of pore structures are observed, namely less wide form, rather narrow form and narrow form. The quality of tight sandstone reservoir is mainly controlled by throat. The results show that the research area has characteristics of the low stress sensitivity, high brittleness index and small horizontal principal stress difference. It's suitable for SRV fracturing.