1. A method for acquiring classification functions or facial age identification, the method comprising: acquiring a plurality of facial images associated with different ages; assigning the facial images into a plurality of facial image collections based on at least information associated with a plurality of first age groups, wherein a first age group corresponds to a facial image collection and a facial image collection includes one or more facial images; for a first age group, acquiring one or more first facial image collections associated with one or more second age groups older than the first age group as positive samples; acquiring one or more second facial image collections associated with one or more third age groups younger than the first age group as negative samples; and performing training based on at least information associated with the first positive samples and the negative samples to determine one or more classification functions for the first age groups.