Method for enriching target nucleic acid sequence from nucleic acid sample

Provided is a method for enriching a target nucleic acid sequence from a nucleic acid sample, the method comprising: providing a nucleic acid sample containing a target nucleic acid sequence and a bait sequence identical to the target nucleic acid sequence or having characteristics against the target sequence; preparing a nucleic acid analogue by in vitro transcription using the bait sequence as a template, with the nucleic acid analogue carrying a binding portion; fragmenting the nucleic acid sample; hybridising the nucleic acid analogue with the nucleic acid sample, such that the nucleic acid analogue and the target nucleic acid sequence form a nucleic acid analogue/DNA hybrid complex; and isolating the nucleic acid analogue/DNA hybrid complex from a non-specific hybrid nucleic acid via the binding portion, and removing the non-target nucleic acid sequence. In a preferred embodiment, the method also comprises amplifying the nucleic acid analogue/DNA hybrid complex so as to achieve the object of enriching the target nucleic acid sequence.