Embodiments of the present invention disclose a fault analysis method based on a data center. The method includes obtaining a topology structure diagram, where nodes in the topology structure diagram include component devices of the data center and a virtual machine running on the data center. The method also includes, when a fault occurs in the data center, obtaining a fault alarm and determining, according to the topology structure diagram, whether the fault reduces communications paths between virtual machines in a virtual machine group running on the data center.