Topology method of peripheral component interconnect, network topology system and method

A topology method of peripheral component interconnect includes: by each of switches, upon receipt of device data from each of terminal devices and the switches that coupled to the switch, transmitting link data that only indicated the terminal devices coupled to the switch to a root complex; and a host obtain a topological spanning tree based on the link data received from the root complex. A network topology method includes: by each of switches, upon receipt of a request packet from a terminal device, transmitting the request packet to a host terminal only through a first connection port coupled to the host terminal; and upon receipt of a response packet from the host terminal, transmitting the response packet to the terminal device only through a third connection port coupled to the terminal device.