Embodiments of the application provide a control channel transmission method, a network device, a network controller, and a terminal device, to avoid a resource collision between physical downlink control channels (PDCCHs) of a plurality of network devices. The method includes: receiving, by a first network device, resource group indication information sent by a network controller, where a resource indicated by the resource group indication information does not overlap a resource used by another network device; determining, by the first network device, a first search space based on a user equipment UE-specific search space and the resource group indication information; and sending, by the first network device, a first PDCCH to the terminal device through the first search space.