Abstract: In this paper, a new drum-type rotor was designed on the basis of characteristics of carbon-fiber-reinforced silicone rubber composites, and its mixing behavior and effect on the residual fiber length in the silicone rubber/carbon fiber composites were analyzed by a numerical simulation software and then verified by experimental results. The results indicated that the rotor configuration, rotor speed and mixing time were major factors determining the residual fiber length, and the DR-I type rotor was found to damage the fiber more seriously. The fiber damage became more serious with increasing rotational speed and mixing time, thus leading to a decrease in residual fiber length.