An optical network-on-chip and a method and an apparatus for dynamically adjusting optical link bandwidth is presented, wherein each fixedly interconnected optical transceiver in a cluster in the optical network-on-chip is configured to establish a link between the cluster and one cluster in other n-x clusters to exchange an optical signal; and a main controller is configured to allocate x adaptively interconnected transceivers to k fixed links with the heaviest communication traffic according to a set rule and communication traffic of fixed links established by n-x fixedly interconnected optical transceivers in the cluster; and for an adaptively interconnected optical transceiver in the x adaptively interconnected optical transceivers, control the adaptively interconnected optical transceiver to establish a link, except the fixed link, between two clusters connected by the fixed link.