Abstract: The reasons of unqualified mechanical performance of large specification 10 steel forgings were analyzed.The results show that the coarse grain is the fundamental cause of unqualified mechanical performance of 10 steel forgings.High initial forging temperature and slow normalization cooling speed after forging cause coarse grain.The unqualified 10 steel forgings are saved by secondary normalizing and adjusting the cooling mode.Reducing the initial forging temperature and improving the normalizing cooling speed ensures that the mechanical properties of large specification 10 steel forgings meet the technical requirements.