The specific functions of biomacromolecules such as proteins or nucleic acid highly depend on their three-dimensional structures.Folding kinetics investigation could reveal the mechanism of how the biomolecules transform from the free linear structure into the functional high-level structure,thus much attention has been paid to this scientific field recently.The biomolecular folding events often occur in the time scale of millisecond or even microsecond,which means that it is necessary to initiate the reaction before that time limit.Ultra-fast micromixer could initiate reactions in a short period of time and has been recognized as an attractive tool to analyze the kinetics of fast reactions.The research progresses of ultra-fast micromixers and their applications in the folding kinetics of biomacromolecules are summarized in this review.