The feasibility of γ-PGA/MoS2 nanocluster synthesized with the assistance of γ-poly glutamic acid (γ-PGA) is discussed. Thermal conversion performance of γ-PGA/MoS2 nanocluster under near-infrared laser is analyzed. γ-PGA and (NH4)2MoS4 which is the precursor of MoS2 nanosheet are dissolved into distilled water, and γ-PGA modified MoS2 nanocluster is synthesized from bottom to top with hydrothermal method. The diameter of nanocluster is (197.3±26.6) nm. Nanocluster configuration may be relevant to the coordination between Mo4+ ion and oxygen atom belonging to the carboxyl group of γ-PGA. During the hydrothermal reaction process, generated MoS2 nanosheets may form clusters due to the existence of coordination, and the oxygen atoms in γ-PGA molecular chain are the center. Nanoclusters show excellent colloidal stability, photothermal conversion performance (with mass extinction coefficient of 11.23 L·g-1·cm-1) and admirable cytocompatibility, and they are expected to be applied to the field of photothermal therapy for tumor.