This application discloses a network slice management method and a device that is designed to improve network slice deployment efficiency. In the network slice management method, after obtaining indication information of a network slice template and performance requirement information of a target network slice, a first network management device may determine deployment information of the target network slice based on the two pieces of information, and may manage the target network slice based on the deployment information of the target network slice, without manual involvement. Therefore, network slice deployment efficiency can be improved.