1. A method for generating a strong classifier for face detection, the method comprising: determining, according to a size of a prestored image training sample, a parameter of each of one or more weak classifiers of the image training sample; obtaining, according to a preset threshold of each of the one or more weak classifiers and the parameter of each weak classifier, a sketch value of each of the one or more weak classifiers of the image training sample; calculating, according to the sketch value of each weak classifier and an initial weight of the image training sample, a weighted classification error of each of the one or more weak classifiers of the image training sample; obtaining, according to the weighted classification error of each weak classifier, one or more optimal weak classifiers; and generating a strong classifier for face detection according to the one or more optimal weak classifiers.