The fiber morphology of aspen BCTMP treated by the high-shear fiber kneader was investigated in this paper. The main process parameters were measured including: rotational speed of screw, pulp consistency of entrance and exit, pressure and temperature of pulp. The results showed that the main action of high-shear fiber kneader on fibers was promoted the relative displacement of exterior and interior fibers, rather than the cutting fibers. After the treatment by the high-shear fiber kneader under high consistency pulp, the shives could be reduced by 95%. The fiber morphology was obviously different from the control samples. With the exit pressure of high-shear fiber kneader increased, the fiber length, fiber width and fiber coarseness decreased, but the index of curl and kink increased.