The invention discloses nucleic acid and a kit for detecting a human HLA-B*5701 allele; a detection method, which is high in specificity, sensitivity and accuracy and simple in operation, for detecting the human HLA-B*5701 allele is established at the same time. The detection method provided by the invention adopts fully closed tube operation, and is simple in operation, convenient and fast; a detection result can be obtained by directly detecting a fluorescence signal value in a polymerase chain reaction (PCR) process, and PCR post-treatment or electrophoresis detection is not needed, so that the problems that the conventional PCR technology easily causes pollution and generates false positive are solved; the method can effectively avoid the problem of non-specific amplification, and is suitable for detection of large-batch samples.