By comparing the existing operation modes of the parallel runways, a selection strategy for runways is given based on the principle of optimizing fuel consumption. Then according to the airline schedules and the separation standard, a mathematical model is established, and a selection and ordering method for runways is proposed based on the fuel consumption optimization. An example indicates that the method can enhance the efficiency on the mixed operation mode of parallel runways, reduce the taxi time and holding time of aircrafts, as well as debase the operation cost of airlines.