The invention relates to a primer, a probe, a composition and a method for screening and identifying MLL rearrangement correlated fusion genes by utilizing a multi-fluorescent polymerase chain reaction (PCR) technology. The screened MLL rearrangement correlated fusion genes comprise thirteen relatively common fusion genes, i.e., MLL-AF9, MLL-AF6, MLL-AF4, MLL-AF1P, MLL-AF1Q, MLL-AF10, MLL-AF17, MLL-AFX1, MLL-ELL, MLL-ENL, MLL-SEPT6, MLL-CBP and dup MLL. The primer, the probe, the testing combination way and the detection method are convenient, economical, fast, good in specificity, high in sensitivity and large in flux, thus being suitable for clinical test of large-batch samples.