An architecture for improving reliability of a multi-server system is provided. The hard disk backplane is provided with at least two hard disk modules, each of which includes a power supply isolation unit and a signal isolation unit. The power connection board is connected to the power supply isolation unit in each of the at least two hard disk modules, so that power supplies of the at least two hard disk module are isolated from each other. Each of the at least two server nodes is connected to at least one of the hard disks through a corresponding signal isolation unit. The server node, the signal isolation unit and the hard disk which are connected to each other form an isolated data communication group. Signal isolation units in any two of isolated data communication groups belong to different hard disk modules.