The experiment of chaotic exponent extraction is carried out on the basis of nonlinear vibration system, and the responses under different conditions are processed with the improved algorithm. Firstly, the weighted wavelet denoise method is applied to filter the contaminated noise. Then, on the basis of fast search technology i.e. space grid hiberarchy inquiry method, the chaos characteristic exponent extraction algorithm is modified and applied to LE and fractal dimension calculation. Finally the piece-wise vibration system is designed, and the nonlinear dynamics under different harmonic frequencies excitation are analyzed. The comprehensive chaos judgment program is developed, in which the time domain diagram, phase space reconstruction attractor, Lyapunov exponent, fractal dimension curve of the measured data are obtained. The interesting phenomena such as AM modulation, limited cycle, and strange attractor are observed.