Abstract: A service board includes a flexible board, at least one chip, and at least one optical cage layer. Each optical cage layer includes a plurality of optical cages. Each optical cage has an opening that faces a panel side and that is configured to connect to an optical module. The optical cage includes a housing and a plurality of signal pins. One end of the flexible board is electrically connected to tail ends of the plurality of signal pins, and another end of the flexible board is electrically connected to one chip, thereby shortening a connection path between the optical module and the chip, and reducing a link loss. Therefore, integration of the service board is improved, assembly is convenient, and a high-density connection and a simplified design of the service board are implemented, so that the service board is applicable to a high-density and high-speed transmission scenario.