Electro-slag remelting (ESR) is a kind of special metallurgy techniques to produce high quality alloy materials. The interface of electrode and slag is the energy entrance of entire system in the remelting process. Mathematical model of consumable electrode’s melting process has been built in this paper. Some valuable variation rules of droplet diameter, droplet forming time, melting rate and purification coefficient following melting current and slag bath depth have been studied through a series of simulation work. Based on the mechanism studying of the consumable electrode’s melting, some meaningful experience to optimize the technological parameters and improve material quality of electro slag ingot has been gotten.