The invention aims at providing a solution melt co-spinning electrospinning device for preparing composite fibers. The device comprises a first sleeve, a second sleeve, a third sleeve and a fourth sleeve which are nested with one another in sequence, straight flow channels and annular flow channels are formed among the sleeves and used for flow of gas and melts, a needle head is fixed to the lowerend of a central pipe from the interior of the fourth sleeve, the top of the central pipe is connected to an injection pump through an insulated guide pipe and connected to a high-voltage electrostatic generator, and jetting of a solution is formed at the tip of the needle head; a high-voltage electric field is formed between the annular tip of the first sleeve and the needle head, the annular tip is inductively charged, the melts are self-organized to form a uniformly distributed multi-jet, and the annular airflow prevents solution-spun fibers from flying to the annular tip; moreover, the two fibers are stretched to reduce the fiber diameter, and the fibers formed by the melts and the solution are entangled and adhered to each other during jetting to form the composite fibers. The devicehas the advantage that composite fiber membranes with high porosity, a high specific surface area and high strength can be prepared.