In this work, a SAR micromixer with F-shape mixing units is analyzed by simulation and experimentation. The results prove that the mixing performance of SAR micromixers with F-shape mixing units has a huge advantage over that of T micromixers. A satisfactory mixing efficiency can be achieved by splitting-recombination and chaotic advection mechanisms. The results indicate that when the Reynolds number increases from 0.5 to 15, the mixing efficiency of the two micromixers decreases. And at Re = 15, the lowest mixing efficiency of the SAR micromixer is 54%. When the Reynolds number increases from 15 to 50, the mixing efficiency of the SAR micromixer reaches about 90%. When the Reynolds number exceeds 50, the mixing efficiency of both micromixers begins to decrease. And the mixing performance of the SAR micromixer with F-shape mixing units is superior to that of the T micromixer.