This study takes the consumable electrode, slag bath, and ingot as investigated objects. Mathematical models is established based on the convection thermal transfer equation of the slag bath, the thermal conduction equation of the ingot, and the melt flowing equation,meanwhile the appropriate electromagnetic field, thermal boundary conditions are applied, The numerical simulation study on influence of process parameters on filling channels between metal pools in electroslag casting process with fixed consumable electrode filling method are performed by using large finite element analysis software ANSYS. Size of casting ingot is 400 x 70 x 400, the research show that when the current density of mobile consumable electrode is greater than or equal to 0.5 A/mm<sup>2</sup>, the electrode spacing is less than or equal to 0.15m, and the electrode thickness is greater than or equal to 0.035m, the two metal pools are connected,molten metal of moved consumable electrode casting successfully supply the metal pool of fixed consumable electrode through filling channel, make sure that casting is forming under stable electroslag conditions. the minimum sectional area of filling channel is increased with the increase of current density of the mobile consumable electrode and the cross-sectional area of the consumable electrode.