Combined fan structure

The invention relates to a combined fan structure, which belongs to the technical field of fans, and comprises a plurality of sub-fans and connecting pieces connected between two adjacent sub-fans, the sub-fan comprises an impeller mounting shell and an impeller assembly mounted on the impeller mounting shell, two inserting grooves are formed in the two side faces, away from each other, of the impeller mounting shell respectively, and inserting openings used for allowing the connecting pieces to be inserted into the inserting grooves are formed in the groove walls of the two sides, away from each other, of the two inserting grooves. Limiting strips are arranged on the side walls of the two sides, adjacent to the inserting opening, of the inserting groove, a limiting channel is formed between the limiting strips and the groove bottom of the inserting groove, and the limiting channel communicates with the inserting opening. A clamping groove is formed in the groove bottom of the inserting groove, and when the c