The large eddy simulation (LES) is used to study the fully developed flow fields in Kenics statics mixer. The formation inducement and evolution process of secondary flow is analyzed. Simulated data coincide well with experimental data. The results based on the current researched contents show that there are three kinds of longitudinal vortices in the area of the seventh twisted element. They are designated as merged-vortex, internal- vortex and detour-vortex. Merged-vortex produces by merging two vortices from the entrance of element. And internal- vortex grows by the rotation of the twisted blade. The detour-vortex is induced by the Coriolis force caused by high twist rate of the twisted blade. And the Coriolis force will lead to the unbalance pressure distribution and the separation of boundary layer, thus the induced vortices will come into being. The area of the seventh element is divided into four segments along the axial direction. There are five vortices in the first and second segments, and the values of vorticity and turbulent intensity are 23.0% and 8.93% higher than that in the third and fourth segments respectively. The vorticity increases suddenly near the pipe wall on the interface of the neighboring elements, which is 73.0% higher than the average values, because the energy dissipation is caused by breakup and coalescence of vortices.