The development of high-performance static mixers is a critical research topic in process intensification in the process industry. This research combines computational fluid dynamics simulation and experimental testing to design a new type of static micromixer: First, a variable-diameter swirl shear mixer was designed and its structure was optimized. Measured by Malvern laser particle size analyzer, the median particle size decreased from 41 μm to 29 μm in the designed micromixer compared to that of traditional static mixers. Subsequently, the dispersed phase injection method was upgraded to a jet injection method, and the static micromixer was designed with a combination of an ejector and a variable-diameter swirl shear mixer. The median particle size of the dispersed droplets further decreased to 23 μm, achieving a dispersion effect at 2100−2400 rpm of the dynamic high-shear mixer. The micromixer greatly improved the static mixing effect and may replace dynamic high-shear mixers in the future.