Abstract: Displacement experiments of secondary polymer flooding by micro visual model show that recovery can be enhanced through improved oil-water mobility ratio for non-homogeneous reservoir before secondary polymer flooding in H2 Ⅱ oil group of Xiaermen oilfield.Sweep region and flooding effect in various stages for water flooding,primary polymer flooding and secondary polymer flooding are reported at the same time.It is an important reference that optimization chemical flooding for further enhanced oil recovery at the end of water-drive after primary polymer flooding at home and abroad