The invention discloses application of a dual PCR (polymerase chain reaction) detection kit in non-diagnostic and non-therapeutic identifying and distinguishing of prevalence floras from non-prevalence floras of vibrio parahaemolyticus. The detection kit comprises direct hemolysin gene detection primer pairs of which the sequences are shown as SEQ ID NO.1 and SEQ ID NO.2, and tlh (thermolabile hemolysin) detection primer pairs of which the sequences are shown as SEQ ID NO.3 and SEQ ID NO.4. The dual PCR detection kit is adopted to remove infectious microbe interference, replaces multiple vibrio parahaemolyticus virulence genes for detection, and screens whether vibrio parahaemolyticus exists or not in a sample through tlh and whether big prevalence floras of vibrio parahaemolyticus exist or not in the sample at the tdhl-368, so that the prevalence floras and the non-prevalence floras of vibrio parahaemolyticus are distinguished through one-time amplification, the improvement on the detection sensitivity and the specificity of conventional epidemic strains is facilitated, and the dual PCR detection kit is simple, convenient and effective.