Quantum signature is an effective approach to identity authentication for single stream in quantum networks,but it is constrained in the crossing case of multiple streams.To solve this problem,we present a quantum homomorphic signature scheme to enhance the security of quantum networks.By entanglement swapping,this scheme can combine two quantum signatures and generate a new homomorphic signature.Analysis results show that the proposed signature scheme can effectively guarantee the security of secret key and verify the identity of different data sources in a quantum network.