The present disclosure provides a multi-CPU system, where the multi-CPU system includes: at least two Quick-Path Interconnect QPI domains, a first node controller NC group, and a second node controller NC group; according to a CPU route configuration, there is at least one CPU that can access a CPU in another QPI domain by using the first NC group; and there is at least one CPU that can access a CPU in another QPI domain by using the second NC group. According to this topology, hot swap of an NC can be implemented while the system is relatively slightly affected.