The electrowetting triple-liquid lens has excellent zoom performance, but its structural complexity and design difficulty are relatively high. Therefore, we propose a method for optimizing the structural parameters of the electrowetting triple-liquid lens based on joint simulation. To design a triple-liquid lens, Comsol and Zemax software are used to establish triple-liquid lens simulation models under different structural parameters, and its focal lengths under different voltages are obtained. The effects of height and taper on zoom range and initial focal length are analyzed, and a set of structural parameters with the maximum zoom range and the longest initial focal length is determined. To verify the method’s reliability, we prepare the triple-liquid lens models with different heights and tapers, and conduct zoom experiments. The simulation and experimental results show that the initial focal length of the triple-liquid lens correlates positively with height and taper; the zoom range correlates positively with taper, but height is the main influencing factor. When the height is 12 mm and the taper is 20°, the lens has the most extensive zoom range and the longest initial focal length. When the taper is less than 15°, the simulation and experimental results are highly consistent.