Abstract: Focusing on the disadvantages of the Real Adaboost algorithm selected smoothing factor.This article proposes DS-Adaboost algorithm,this algorithm dynamic select smoothing factor in weak classifier output,According to the size of the ratio of W^j₊₁W^j－1 dynamic selected smoothing factor．When W^j₊₁W^j－1>1,ε_j=W^j₊₁,0j₊₁W^j－1<1,ε_j=W^j－1.The experimental results indicate that the DS-Adaboost algorithm can better play the role of balance,make the proportion of two types of samples are within can match.

Key words: Real Adaboost algorithm,Smoothing factor,Weight update,Face detection