The invention provides a method for calculating heat loss of a high titanium slag smelting large direct current airtight electric furnace. Heat loss generated in the furnace top spraying process, heat loss generated in the furnace wall pipeline cooling process, heat loss of a furnace bottom draught fan, heat loss of furnace top center pieces and heat loss of a furnace bottom high current bus are respectively calculated through the formula Q=CM delta t, wherein C in the formula represents specific heat of water, M represents mass of water, and delta t represents the difference value between the temperature and a water pipe and the water inlet temperature; then the heat loss value of the electric furnace can be obtained by adding calculated values of all parts. The heat loss of the high titanium slag smelting large direct current airtight electric furnace can be accurately calculated, the working process is simple, easy to monitor, and safe and reliable, maintenance is simple, practicability is high, and the method plays an important guidance role in adjusting energy balance technological parameters of the continuous smelting high titanium slag smelting large direct current airtight electric furnace.