The paper is aimed to study the profile evolution of microlens fabrication in short duration from several mini-seconds to seconds. Droplet deposition method, similar as inkjet-like printing, could be applied for the 3D lens-making process, in which optical liquid material was used here. The transient mechanism of lens-forming behavior is fully understood by using numerical simulation of fluid thermodynamics. Deposition results can be shown that concave and convex profiles are determined by a couple of physical parameters, such as solid content percentage and evaporation rate. With the experiments, it is expected that the rapid method can be further implemented in many manufacturing of small objects in the future.