Jurassic Yan’an Formation is the main oil-bearing strata in Ordos Basin，the study of reservoir characteristics and microscopic waterflooding percolation characteristic has not been paid enough attention. Taking Yan8 Formation of Yanwu Oilfield in Ordos Basin as an example，the waterflooding front distribution features，oil-water percolation rule and residual oil state of various waterflooding types are clarified based on the reservoir characteristics analysis and real sandstone microscopic waterflooding experiments. The relationship between microscopic displacement efficiency and pressure is built，and forming mechanism and distribution rule of the residual oil are summarized. Microscopic waterflooding types in the study area can be divided into four types：uniform flooding type，network flooding type，network-finger flooding type，and finger flooding type. With the increase of unit displacement pressure，the displacement efficiency of uniform displacement model changes most obviously，followed by network flooding，network-finger flooding and finger flooding types are worst. Affected by the physical properties of rock particle surface and the pore throat structure，the different displacement types have different proportion of residual oil types after waterflooding. The residual oil types of uniform displacement type and network displacement type are mainly oil film and corner shape，the residual oil types of the finger displacement type are mainly sheet and cluster shape，and the network-finger displacement type has a similar proportion of the different residual oil types.