Slab surface quality is closely related to the original shell heat transfer conditions at the beginning of the continuous casting. In this paper, through the establishment of mathematical groove-model at the original shell, calculate effect of different components for groove-mould original shell heat transfer .Simulation results show that different components for groove-mould original shell heat transfer has effect .The more Solidification shrinkage, the more late forming original shell. Temperature＇ s not uniformity and stress both increase. If solid and liquid phase region is wider ,forming original shell is too late, but temperature＇ s not uniformity and stress are reductive. The simulation results of 06F is the first one to form a original shell, Q235 is the second, and 45^# in the last. Maximum stress of shell is from simulation results of Q235 and minimum stress is 45^#.