The invention discloses a method for constructing series connection RAD [restriction-site-associated
DNA (deoxyribonucleic acid)] tag sequencing libraries. The method includes steps of 1), carrying out
enzyme digestion reaction on
DNA by the aid of incision enzymes; 2), respectively connecting linkers to
enzyme digestion fragments; 3), amplifying connection products, to be more specific, carrying out PCR (
polymerase chain reaction) amplification by the aid of
biotin primer and common primer combinations, enriching PCR products, recycling the PCR products by means of gel incision, amplifying the PCR products again, equivalently mixing the PCR products with one another and equivalently purifying the PCR products; 4), serially connecting tag libraries with one another, to be more specific, carrying out
enzyme digestion on the PCR products by the aid of SapI enzymes and sequentially serially connecting the PCR products with one another; 5) enriching series connection long tags, to be more specific, purifying the series connection long tags by the aid of gel, then carrying out PCR amplification by the aid of primers and introducing
barcode to construct the libraries; 6), carrying out
library sequencing. The linkers are provided with
enzyme digestion sites of the SapI enzymes, signature sequences for serially connecting the tags with one another and universal sequences for binding the amplification primers. The method has the
advantage that genetic markers and epigenetic variation can be screened and detected in whole
genome ranges by the aid of the method in a high-
throughput and low-cost manner.