Abstract: This paper proposes a universal steganalysis system for JPEG images.Several kinds of steganography algorithms are used for embedding the secret information into images.Then this paper effective analyzes the experiment of the characteristic function for the coefficients of the wavelet decomposition details and approximation components.This paper also further decomposes the first scale diagonal D₁ subbands and obtains the coefficients of the details and approximation components.Then does the same effectiveness analyses experiment for the characteristic function moment of the coefficients.The L-M algorithm BP neural network is adopted to train the feature set.This paper gets better detection results through the experiment for JPEG images.