Application method of submerged-arc welding agent for welding cabin cover

The invention discloses an application method of a submerged-arc welding agent for welding a cabin cover. The application method comprises the steps of: (1) placing the submerged-arc welding agent in an environment with the temperature of 300-400 DEG C for 2 hours to carry out drying work; (2) welding the cabin cover by using the dried submerged-arc welding agent; taking CO2 as protection gas, wherein the water content in the CO2 gas is less than 0.05%. The submerged-arc welding agent is placed in the environment with the temperature of 300-400 DEG C for 2 hours to carry out the drying work so that the water content of the submerged-arc welding agent is greatly reduced; when the submerged-arc welding agent is used, the water content of the protection gas CO2 is less than 0.05% so that the welding quality of the cabin cover can be improved.