For homogeneous mixing of a polymer melt and micro/nano-inorganic particles, the researchers in our group developed a three-dimensional dynamic mixer with comprehensive effects of dispersion and distribution. To evaluate the distributive mixing effect, the expressions of diversion number and mixing degree were deduced according to the structure parameters of the mixer. To further investigate the diversion state of the melt and its velocity field in the mixer, this process was simulated with computational fluid dynamics (CFDs) software. In a pilot study, the working curves of the mixer were plotted according to the actual running state. Among other things, the pressure drop before and after mixing is discussed. This is helpful for formulating an extensional flow field and relevant to the dispersive mixing effect. Through laboratory and industrialized scale experiments it was determined with either very high or very low additions of inorganic particles, that the mixer can provide uniform and ultrafine dispersions.