The invention discloses a method for fixing a DNA basic group to the surface of a glass slide. The method is suitable for fixing the DNA basic group to the surface of the glass slide. Firstly, the glass slide is cut into small pieces, washed, immersed in 95 percent of HCL and 99.7 percent of absolute ethyl alcohol mixed solution, processed through acid, and then is washed. Secondly, the glass slide is immersed in an APTES absolute ethyl alcohol to be prepared into a silanized glass slide. Thirdly, the silanized glass slide is immersed into a glutaraldehyde glutaraldehyde water solution to be reacted and flushed and is aired to be used later. Fourthly, a buffer solution is prepared, cosolvent and a surface active agent are added to the buffer solution to prepare a surface active agent solution, the DNA basic group is added to the surface active agent solution, full stirring is carried out to enable the DNA basic group to dissolve completely, and a DNA solution is prepared. Fifthly, the DNA solution is sampled to be dripped on the glass slide, the sampled DNA solution is cultivated in a calorstat at the appropriate temperature and is cleaned, and fixing of the DNA basic group is finished. By means of double modification of the glass slide, the wettability of the glass slide is improved, and the fixing rate of the DNA basic group is improved. Representation is carried out on the DNA basic group through a laser confocal raman spectrometer, the steps, needed in light splitting method of fluorescence, of fluorescence labeling and gene amplifying and hybridizing can be removed, and the DNA basic group fixing steps are greatly simplified.