The invention discloses a multiplex DPO-PCR (dual-priming oligonucleotide-polymerase chain reaction) detection kit for sunflower white rust and black stem and application thereof. The multiplex DPO-PCR detection kit comprises a primer set for detecting or auxiliarily detecting whether the detected strain is sunflower white rust or sunflower black stem, wherein the primer set is composed of a primer 1, a primer 2, a primer 3 and a primer 4. The test proves that the DPO primers and detection kit have the characteristics of favorable specificity, high accuracy and high sensitivity and can be used for detection, differentiation and identification of sunflower white rust and sunflower black stem.