Disclosed are a host discovery and addition method and apparatus in a data center, and a device and a medium. The method includes: scanning to discover computing nodes to be added; sending, through IPv6 multicast, a discovery message to the scanned computing nodes, and receiving discovery response messages that are sent by said computing nodes through IPv6 unicast after the discovery message passes verification; when the discovery response messages pass verification and no IP address is configured for said computing nodes, sorting BMC IPs in the discovery response messages, and allocating IP addresses according to the order of the BMC IPs, such that the IP addresses that correspond to adjacent BMC IPs are consecutive; and after the IP addresses are configured, sending an addition message to said computing nodes, receiving addition response messages, and adding said computing nodes to a data center that is managed by a management node.