The present disclosure provides a method for training a convolutional neural network and a method and device for face recognition. By arranging a first training sample set including a first data set and a second data set, the convolutional neural network is trained and may be applied to the face recognition method, an initial face image frame may be extracted from a face detection image, in the face recognition method, a portion above eyes is cropped from the initial face image frame to serve as a target face detection image, thus according to the target face detection image, predicted identity information corresponding to the target face detection image is determined, and then the target face detection image is compared with a face reference image corresponding to the predicted identity information for face recognition.