The utility model discloses a welding slag receiving device. The welding slag receiving device comprises a slag receiving box; an air return hole is arranged at one side of the slag receiving box; and a draught fan is arranged in a position of the slag receiving box corresponding to the air return hole. According to the technical scheme, the air return hole is arranged on the slag receiving box, and the draught fan is arranged in the position corresponding to the air return hole, thereby air flow is generated at the upper part of the slag receiving box through the operation of the draught fan so that negative pressure is generated and drives welding slag to enter the slag receiving box. The welding slag is concentrated in a slag storage tank; and an air return hole is arranged at the upper part of the slag storage tank so as to keep air fluent. Therefore, the welding slag receiving device has the advantages of convenient in use, good welding slag collection effect and the like.