Abstract: A new nonlinear method-chaotic analysis was used to analyze the pressure fluctuation in the impinging region of SCISR. The signals of pressure fluctuation were filtered by using the wavelet theory. The chaotic attractors were reconstructed on the basis of the phase space theory.Three characteristic parameters to describe chaos, such as correlation dimension, Kolmogorov entropy and Lyapunov exponent, were calculated. The chaotic profiles were shown in the impinging region of SCISR by studying the value of these three parameters at different rotary speeds and on different positions of area-y.At the same time, the trend of these three parameters changed similarly at different rotary speeds and on different positions.