  Building communication links among multiple users in a scalable and robust
way is a key objective in achieving large-scale quantum networks. In realistic
scenario, noise from the coexisting classical light is inevitable and can
ultimately disrupt the entanglement. The previous significant fully connected
multiuser entanglement distribution experiments are conducted using dark fiber
links and there is no explicit relation between the entanglement degradations
induced by classical noise and its error rate. Here we fabricate a
semiconductor chip with a high figure-of-merit modal overlap to directly
generate broadband polarization entanglement. Our monolithic source maintains
polarization entanglement fidelity above 96% for 42 nm bandwidth with a
brightness of 1.2*10^7 Hz/mW. We perform a continuously working quantum
entanglement distribution among three users coexisting with classical light.
Under finite-key analysis, we establish secure keys and enable images
encryption as well as quantum secret sharing between users. Our work paves the
way for practical multiparty quantum communication with integrated photonic
architecture compatible with real-world fiber optical communication network.
