Shale oil is an important component of unconventional hydrocarbon. It mainly exists in different types of pores and fractures of shale. Unlike the shale at high maturity stage which generate shale gas，hydrocarbon pore space in organic shale at oil-generating window is often filled completely or partially by early hydrocarbon-generating materials，thus affecting the structure characterization and geometry description of shale oil pore spaces. Through the microscopic observation of a large number of shale samples，the pores of shale oil reservoir could be divided totally into intergranular mineral pore，intragranular mineral pore and organic pore. The former two types of pores include intergranular pore among different mineral particles，dissolution pore，clay mineral interlaminar pore，etc. The organic pores are composed by marginal shrinkage pore （fracture）and a small amount of pyrolysis pore. Based on the requirement for characterization of shale oil pores，solvent extraction was carried out on the samples，and the suitable pore characterization techniques for crushed and blocked samples were discussed respectively. Different shale oil characterization methods have certain differences in principle and application，and have certain limitations as well. In order to avoid the influence of this factor on pore characterization，a variety of characterization methods could be combined to characterize pore through comparative analysis and unified dimension，so as to improve the accuracy of pore characterization results of shale oil reservoir.