Abstract: The effects of control cooling process on the metallographic structure and fracture properties of drop weight tear test（DWTT） of X80 were studied and analyzed through industrial test. The results show that when the finish rolling temperature is low, coarse ferrite deformation layer is formed on the surface. And when the finish rolling temperature is high,proeutectoid ferrite with less carbide and larger size is formed. When the temperature of laminar cooling water is high, coarse proeutectoid ferrite is formed instead of acicular ferrite. When surface water accumulation is serious, the proportion and size of quasi-polygon ferrite increase. All the cooling process above may reduce the DWTT properties. As a result, the process optimization scheme is put forward: the finish rolling temperature is controlled at 760-820 ℃, the final cooling temperature is controlled within 500 ℃, and the temperature of laminar cooling water is controlled within 31 ℃. At the same time, strong side spary water is applied to purge surface water on the steel plate. After process optimization, acicular ferrite is obtained on the surface and inside of the steel plate, and the drop weight shear area ratio is higher than 85%.