A thermo-mechanical coupled model has been established by the thermo-elastic-plastic finite element method,in which the contact behavior between thin slab and mold was taken into account,to simulate the temperature field,stress field and longitudinal cracking index variations of carbon steel shell in funnel mold as well as effects of pulling velocity on stress and longitudinal cracking index.The results indicate that the temperature at the thin slab off-corner of wide face is higher than those of at the center of the wide face and narrow face,and the existence of two plateaus of temperature history can be observed at 280 mm and 840 mm below meniscus.The peak stress of solidification shell occurs in the funnel edge where the shell has high cracking susceptibility.The higher longitudinal cracking index occurs in the center,funnel edge and off-corner of thin slab wide face,showing easy occurrence of longitudinal crack.The longitudinal cracking index of initial solidified shell can be decreased to reduce the formation possibility of crack by proper increasing casting speed.