The invention relates to an rTRAIL (recombinant TNF (tumor necrosis factor) related apoptosis-inducing ligand) mutant and a monomethyl auristatin E(MMAE) conjugate thereof. The invention discloses the rTRAIL mutant of which the amino acid sequence is as shown in SEQ ID No.1. The invention also discloses a coding gene of the rTRAIL mutant as well as an expression unit, a recombinant vector or an expression system containing the coding gene. The invention also discloses an rTRAIL mutant-vcMMAE conjugate and a preparation method and application thereof. The conjugate disclosed by the invention has the biological functions of both the rTRAIL mutant and the MMAE, the MMAE is directionally transported to tumor cells through specific binding of the rTRAIL mutant with death receptors on the surface of the tumor cells, and the MMAE is released in the tumor cells to take effect, thus tumor cells with low sensitivity or even resistance to TRAIL can be killed, and the toxic side effects generated due to individual administration of the MMAE are also reduced.
