Here, we report a novel metal-organic framework ZIF-8-based nanocomposite with encapsulated molybdenum disulfide(MoS2)nanosheets and doxorubicin(DOX)for pH- and NIR-triggered synergistic chemo/photothermal treatment of cancer cells. First, MoS2 nanosheets, which have uniform size of ~100 nm and topological height of 0.3~1.4 nm, are synthesized by hydrothermal reaction and ultrasonic treatment. Subsequently,an acid-degradable metal-organic framework ZIF-8 is employed to synchronously encapsulate MoS2 nanosheets and anti-cancer drug DOX to obtain DOX loaded ZIF-8 coated MoS2 (DOX/MoS2@ZIF-8)nanocomposites by one-step method. The nanocomposites are used for chemo/photothermal synergistic treatment of cancer cells: under acid conditions (e.g. pH 5.0 in a lysosome)and NIR laser irradiation (780 nm, 2.1 W/cm2), the ZIF-8 of the DOX/MoS2@ZIF-8 nanocomposites can be degraded, resulting in the release of encapsulated DOX, the cytosolic DOX can enter the nucleus to induce apoptosis. Meanwhile, the MoS2 nanosheets can effectively convert NIR laser light energy into heat energy, the photoinduced hyperthermia can also induce apoptosis. Thus, chemo/photothermal synergistic cancer therapy is realized. Cell viability assays show that this DOX/MoS2@ZIF-8 nanocomposites have an excellent chemo/photothermal synergistic treatment effect on SMMC-7721 cells, which can kill the tumor cells efficiently.