With the popularization and spread of SDN, the size of SDN networks is increasing; the controller placement is a key problem in software defined networks (SDNs). In this paper, an optimized controller placement method is proposed, which takes into consideration the load of controllers, co-located deployment and propagation latency to determine the optimal number and location of controllers. Firstly, multi-objective genetic algorithm is used to get the connection relationship of controllers and switches, so the network can be partitioned into several domains. Secondly, minimum delay algorithm is adopted to find an optimal location which has a minimizing sum of the distance to the other points in each domain. Finally, in this article, the results obtained from the analytic and experimental performance can evaluate the benefits that could be achieved by deploying our scheme for the SDN controller placement problem.