Cepstrum method is a traditional characteristic parameter detection algorithm in the modern in the speech signal processing . it is one of the speech signal using the cepstrum features, to detect the representation glottis incentive cycle pitch information.In order to eliminate the influence of the fundamental frequency harmonic, we utilize the homomorphism solution volume technology, getting smooth spectral envelope.While the artical analyses cepstrum from out of the signal deleted to the short time window , detect speech signal pitch information;Then the signal of Fourier transform, take the logarithmic spectrum amplitude envelope, to analyze the speech signal formant parameters. The speech signal characteristic parameters have higher accuracy than ones from the traditional cepstrum method.