Display omitted •A redox prodrug co-loading camptothecin and curcumin was prepared.•The co-delivery system showed a synergetic inhibition effect to B16 melanoma cells.•The co-delivery system showed a good biocompatibility. A redox prodrug consisting of camptothecin-conjugating PEG through the diselenide bond was synthesized, and the resultant amphiphilic prodrug was then used to load the curcumin to form the co-delivery system for the synergetic B16 melanoma cells inhibition. The co-delivery system showed a good response to glutataione, and the prodrug could be degraded and the two loaded drugs were then released. Both camptothecin and curcumin could induce the obvious cytotoxicity to B16 melanoma cells. Particularly, the co-delivery strategy showed a synergetic inhibition effect to B16 melanoma cells through an in vitro assay. In vivo assay also showed that the co-delivery system could inhibit B16 tumor growth and showed much better inhibition effect than that of only camptothecin or curcumin used. Moreover, as an injectable drug delivery system, the biocompatibility including the blood compatibility of the co-delivery system was confirmed, suggesting that the redox co-delivery system have a potential application in B16 tumor therapy.