Abstract: MoS2@ZnO heterojunction nanomaterials were synthesized by ultrasonic method．The structures and morphologies of MoS2@ZnO heterojunction were characterized by X-ray diffraction (XRD), scanning electron microscopy ( SEM), photoluminescence spectra (PL), and photocurrent density measurement. The SEM results shown that MoS2@ZnO heterojunction composite was composed of ZnO nanospheres about 50 ~ 100 nm in diameter wrapped in MoS2 nanosheets. The results of PL spectra, and photocurrent density measurement shown that the heterojunction between MoS2 and ZnO can effectively separate photogenerated electrons and hole, reduced their recombination probability, and improved their photocatalytic activity. The photocatalytic activity of ZnO, and MoS2@ZnO that the mass ratios of MoS2 were 0.5%、1.0% and 2.0% heterojunction nanomaterials were evaluated by the degradation of Methylene blue (MB) (15 mg/L) solution under 250 W Xe lamp irradiation, the results shown that photocatalytic degradation of MB by MoS2(1.0%)@ZnO heterojunction nanomaterials is 15.2% more efficient than pure ZnO. The photocatalytic stability and the reuse of the catalyst were crucial, recycled experiments for the photodegradation of MB were conducted to study the photostability of the MoS2@ZnO heterojunction nanomaterials, which the mass ratio of MoS2 was 1.0%. The photocatalytic activity of MoS2(1.0%)@ZnO had no significant change after three cycles, MoS2(1.0%)@ZnO exhibited excellent photostability.