The invention provides a fluorescence-labeled composite amplification kit for Y chromosome STR (short tandem repeat) gene loci capable of improving distinguishing capability. When the kit is used for detecting DNA (deoxyribonucleic acid) gene, not only can 17 STR gene loci of DYS391, DYS389I/II, DYS439, DYS438, DYS456, DYS458, DYS437, DYS635, DYS448, Y-GATA-H4, DYS19, DYS392, DYS393, DYS390 and DYS385a/b, which can be analyzed by the commercial kit, be amplified and analyzed, but also at least one of STR gene loci of DYS449, DYS527a/b, DYS522, DYS388, DYS447 and DYS444 can be simultaneously amplified and analyzed, so that the accumulative individual distinguishing capability and cumulative probability of exclusion of the system are improved, and the individual distinguishing capability is improved overall.