In this paper, the two -phase flow behaviors of gas-solid circulating fluidized bed have been first studied by analysing experimental data. Then, based on fractal theory wavelet package analysis(WPA) de-noising method was used to denoise solids concentration and pressure fluctuation signals. The solids concentration signals have also been investigated by wavelet multi-resolution analysis and wavelet package decompose, contributed to disclose the non-uniform flow structures of gas-solids phase. F...