To guarantee network Quality of Service (QoS), network controllers designed and applied in real networks are necessary. How to automatically find efficient parameters of a controller and get the setting time of control system in simulation is a common problem in the process of controller design. Some definitions, experience rules and algorithms based on statistical theory are proposed in this paper, which are able to get the setting time, judge the stability feature of network control system and compare the control effects of different controllers. We tested the algorithms with network congest...