The present disclosure relates to a method for traffic engineering in a communications network. In one example method, a controller determines at least one sampling node in a flexible node and a temporal frequency for traffic sampling. The controller instruct the at least one sampling node to perform traffic sampling at the temporal frequency. The controller receives sampled traffic data of all sampling nodes obtained during each sampling. The controller determines, according to the sampled traffic data obtained during each sampling and information about total traffic of a link whose link utilization is greater than a first preset value or less than a second preset value in the communications network, parameter information for traffic engineering. The controller performs traffic engineering control according to the parameter information.