1. A method for exacting face features from data of face images, comprising: 1) filtering the data of face images into a first plurality of channels of feature maps with a first dimension; 2) computing each of the maps by rule of σ(x)=max(0,x), where x represents feature maps with the first dimension; 3) down-sampling the computed feature maps into a second dimension of feature map; 4) filtering the down-sampled maps into a second plurality of channels of feature maps with a second dimension; 5) computing each of the maps with the second dimension by rule of σ(x)=max(0,x), where x represents the second plurality of channels of feature maps; 6) down-sampling the computed second plurality of channels feature maps into a third dimension of feature maps; and 7) filtering each map of the third dimension of feature maps so as to reduce high responses outside the face region, whereby, intra-identity variances of the face images are reduced and discrimination between identities of the face images are maintained.