Gas mixing flow in willow leaf-like static mixer was studied on both velocity and concentration field. The experimental results showed that deviations of velocity and concentration fields were reached to ideal range and were better than those of national standards. CFD simulation on the mixer flow field exhibited good consistencies in numerical values and distribution of concentration cloud diagram between experiment and simulation. Subsequent studies showed that mixing was promoted by longitudinal and hairpin vortices appeared in tailing wake zone of the mixing element. When gas was passing through the mixing element

a high turbulent flow energy dissipation region formed by turbulence-induced increase of kinetic energy dissipation rate could drive much frequent material transfer. Flow resistance of the entire static mixer also occurred mainly in this high energy dissipation region. To some extent

back mixing after the high energy dissipation region strengthened mixing effect.