A method and apparatus for selecting high and low energy scanning voltages for a dual energy CT scanner are provided. The method may comprise: setting a criterion of selection for selecting high and low energy scanning voltages generating combinations of high and low energy scanning voltages according to all scanning voltages supported by a dual energy CT scanner, wherein each of the combinations may comprise a high energy scanning voltage and a low energy scanning voltage and selecting a combination of high and low energy scanning voltages from the generated combinations of high and low energy scanning voltages based on the criterion of selection.
