Transient fluctuations of liquid slag layer and the slag entrainment in continuous casting mould were simulated by large eddy simulation（LES）.The accuracy of the mathematical models was also verified through the water simulation experiments.The effects of operating conditions on the fluctuation of the slag layer

bare "slag eye" region and the size distributions of slag droplets were analyzed quantitatively.The results show that casting speed has a significant effect on the fluctuation of the slag layer in the continuous casting mould.With the increase of casting speed

the peaks of the fluctuation are moved from the narrow wall of the mould toward the SEN

and the regions of "slag eye" is changed from the asymmetric distribution to the " open" conditions.Meanwhile

the size distributions of entrained slag droplets become wider.SEN insertion depth presents the great effects on the fluctuation of the slag layer

the change of "slag eye" region and the distribution of slag droplet size in the continuous casting mould.