Based on well-core observation, slice, SEM, logging data and stable isotope analysis, the reservoir accumulating space types of Jurassic Badaowan Formation in Che-guai area, northwestern margin of Junggar Basin, are well studied. It is considered that conglomerate in the study area mainly developed primary intergranular pores, secondary intragranular dissolved pore and structural fractures; sandstones in the study area mainly developed primary intergranular pores, secondary intergranular dissolved pore and intragranular dissolved pore. The diagenesis characteristics of compaction, cementation and dissolution are studied. Conglomerate and sandstone of Jurassic Badaowan Formation are in stages A and B of late diagenetic stage. In addition, different diagenesis have different influential mechanism on reservoir space types and physical properties. Compaction can decrease the reservoir accumulating space, and makes the reservoir physical properties become worse. On the one hand, cementation can fill up the reservoir accumulating space, and make the reservoir physical properties become worse, on the other hand, it can support grain skeleton and decrease the influence of compaction, meanwhile, it can provide material for dissolution at the late diagenetic stage. Dissolution is a constructive communicating diagenesis, and it can produce secondary pores and fractures.