The invention provides an IP address allocation method and device for a cloud computing network. The method comprises the following steps: determining an allocable IP address resource network segment in the cloud computing network; determining deployment parameters in the cloud computing network, the deployment parameters comprising categories of services to be deployed, categories of networks to be deployed, quantity of server clusters to be deployed, quantity of physical servers in each server cluster and quantity of virtual servers to be deployed in each physical server; and performing automatic allocation on the allocable IP address resource network segment according to the deployment parameters in the cloud computing network. The method and the device can save manpower, improve the efficiency, avoid possible error of IP address repetition during manual allocation, and realize automatic planning of IP addresses.