A method for managing network slices for the benefit of users monitors and obtains key performance indicators configured by a user, the indicator values being collected in real time and visually presented. When a user wants to optimize the network slices, weightings, value intervals, and variables are applied by the user to target key performance indicators. The network slices are optimized by a particle swarm algorithm configured by the user. A device and a computer readable and permanent storage medium for executing the network slices management method are also disclosed.