Embodiments of the present invention relate to the field of communications technologies. Disclosed are a PCIE-based operation system starting method and a server system. The method comprises: a starting management node receiving an access request sent by a first server through a PCIE network and by using a PCIE port; and the starting management node guiding the first server to have access to an operation system file of the first server to respond to the access request. By implementing the embodiments of the present invention, the expenditure for starting a hard disc can be saved, and the work load for replacing and maintaining the hard disc can be greatly reduced, and the reliability of a server system is improved.