Aiming at the measurement issue of dynamic parameters and behavior characteristics of particle clusters in circulating fluidized bed (CFB) , a multi-parameter simultaneous on-line measurement method of velocity, height and concentration of particle clusters based on light scattering principle is proposed. This method is used to measure the parameters of particle clusters in a twodimensional cold test bench of CFB. The light attenuation signal caused by particle clusters flowing through the measurement zone is obtained. The velocity of particle clusters is obtained from the cross-correlation analysis of the light intensity signals of the upper and lower measurement units. The signal is filtered with low-pass filter, and the height of particle clusters is obtained according to the time difference of the extreme points of the low-frequency signal and the measurement results of motion velocity. At the same time, the concentration is calculated according to the light intensity attenuation. Thus, the multi-parameter on-line measurement of velocity, height and concentration of particle clusters in CFB is realized based on light scattering. The measurement results show that under typical working condition, the velocity of particle clusters in the central zone of riser is quite stable, and the average velocity is 3. 81 m / s. The motion velocity of particle clusters in the near wall zone has large fluctuations, even is negative, and the average velocity is 0. 65 m / s. The concentration of particle clusters in the central zone is less than that in the near wall zone. The height of particle clusters in the central zone is mainly distributed in the range of 20 ~ 40 mm, and the height of particle clusters in the near wall zone is mainly distributed in the range of 30 ~ 60 mm. The results provide an effective measurement method for studying the formation, structure and motion of particle clusters in CFB.