Method for rapid screening of nucleic acid aptamer

The invention discloses a method for rapid screening of a nucleic acid aptamer. After to-be-screened target molecules are fixed on a processed inner wall of a micro pipeline, nucleic acid library molecules of DNAs or RNAs flow through the pipeline to be combined with the target molecules on the inner pipe of the pipeline, and then the library molecules which are not combined or weakly combined with the target molecules are washed away with buffer solution, so as to obtain aptamer molecules combined with a target. The aptamer molecules are amplified to obtain an enriched sublibrary. If the affinity does not meet the predetermined requirements, the process can be repeated many times until the required affinity is met. It is relatively simple and efficient to use the method to screen the nucleic acid aptamer, the method is low in cost and easy to implement, and automation is achieved easily. Meanwhile, the method can further be used for affinity detection.