Abstract: An unsteady-state model of electroslag remehing (ESR) slab ingot is established,and the temperature field of slab ingot is calculated.The metal pool depth at different height of ingot is obtained with different melting velocity.The factors influencing the pool depth and the solidification behavior of ingot are discussed. The results show that melting velocity is the most important influence factor for the pool depth,the system is in the quasi-steady state and the pool depth doesn't change when the ingot gets to a certain height.Meanwhile, the cooling conditions in the bottom of ingot have little effect on the pool depth.