The invention discloses a detection method for detecting 1p/19q combination loss of heterozygosity of chromosome, which comprises the following steps: 1) selecting SNP sites with the same number on 1pand 19q; 2) designing an original primer, modifying a T of each original primer, closest to the 3'end but not at the tail end, into U, if the tail end of the 3'end is T, modifying a second T towardsthe 5'direction into U to obtain a multiplex amplification primer sequence; 3) synthesizing a multiplex amplification primer and dissolving and mixing the multiplex amplification primer; 4) carrying out multiplex PCR amplification; 5) processing the amplification product to enable a single chain of U to form an AP site, and then exposing the 5'phosphoric acid tail end and 3'phosphoric acid tail end of the AP site; 6) sequencing, and judging whether 1p/19q combination loss of heterozygosity occurs on the chromosome according to SNP allelic type frequency. According to the invention, the NGS method based on multiplex amplification is used for detecting Chr1p/19qco-LOH, not only is the detection sensitivity high, and are the specificity and the efficiency high, but also the limitation on samples is small.