Peripheral component interconnect(PCI) bus belongs to the local bus category of the processor system, as an extension of the system bus, the main purpose of PCI bus is to connect the processor and external devices. Since the PCI bus specification was proposed, it has been rapidly recognized and promoted by the majority of manufacturers, and has always occupied an important position in the processor architecture. From the perspective of software use, the spatial configuration of PCI bus is an important content. By analyzing the basic principle of PCI bus space configuration, and combining with the specific requirements of PCI device space configuration under PPC processor architecture, this paper introduces the PCI configuration principle and technical implementation details at the software use level in detail, and gives the relevant example code.