The three-dimensional ultrasound imaging method comprise emitting an ultrasonic wave to a fetal head； receiving an ultrasonic echo to acquire an ultrasonic echo signal； acquiring three-dimensional volume data of the fetal head according to the ultrasonic echo signal； detecting a median sagittal section from the three-dimensional volume data according to features of the median sagittal section of the fetal head； determining a facing orientation of the fetal head in the median sagittal section； displaying the median sagittal section as an image suitable for observation according to the facing orientation of the fetal head.
