Abstract: EQ47 steel is one of the most commonly used steel plate used for offshore platform， In order to produce to meet the quality requirements of EQ47 steel，it is studied ， the hot ductility and plasticity can seriously affect the quality of billet ，In order to guarantee the quality of billet in the production process， the hot ductility and plasticity test was carried out on Gleeble-1500D heat stress/strain test machine ，and analyzing the features of the hot ductility and plasticity .The results indicate that there only was two brittle zones ：the first brittle zones is between 1270℃ and 1370℃ 、the second brittle zones is between 600℃ and 900℃； the fracture of steel is tran granular fracture and inter granular fracture ；the Nb、V 、Ti and its precipitation has a great effect on the hot ductility and plasticity.