Gas-liquid-solid circulating fluidized bed is an important multi-phase reactor. However, due to the complexity of gas-liquid-solid flow and the limitations of flow measuring techniques, the flow behaviors of gas bubbles, liquid phase and solid particles in such a system is still little understood and its industry design and scale-up still relies on empirical methods. In this work, the method of vibration acceleration signal diagnosis together with high-speed image analysis was applied in the first time to investigate the collision behaviors of gas bubbles and solid phases with the walls of the riser in a three-phase circulating fluidized bed. The effects of the superficial gas and liquid velocities, type and holdup of solid particles on the characteristics of the original acceleration signals were studied in the time and frequency domains with the help of statistical analysis, spectrum density analysis, wavelet analysis, short Fourier transform and other methods. The comparison analyses of the acceleration signals with the images were emphasized. The results show that the acceleration signal is a good indicator in identifying the collision origins of gas bubbles and solid particles with the walls of the beds and the multiscale flow behaviors, such as flow pattern transition and aggregation of cluster of solid particles in the gas-liquid-solid circulating fluidized bed.