Static and dynamic continuous cooling transformation (CCT) on 610MPa HSLA Steel Plate for 150,000 m3 Oil Storage Tank Construction were carried out on a MMS200 thermo-mechanical simulation system. It has found that with cooling rate increases pre-eutectoid ferrite, pearlite, granular bainite and lathing bainite will appear in the transformed microstructure. In comparison with static CCT, the transforming points of acicular ferrite, granular bainite and lathing bainite in the dynamic CCT curve shift to the left proving an increased acicular ferrite and bainite transformation area.