Flower-like ZnO/SnS2 heterojunction was constructed as photocatalyst. The heterojunction shows hierarchical architecture structure, in which SnS2 nanosheets are uniformly decorated by ZnO nanoclusters. Compared to SnS2, the ZnO/SnS2 heterojunction displays improved photocatalytic efficiency for degradation of organic dye MB and hydrogen evolution. ZnO/SnS2 heterojunction reveals an optimal hydrogen production rate of 346.1 μmol h−1 g−1, about 2.7 times higher than SnS2. The boosting photocatalytic performance is ascribed to the special hierarchical structure and synergetic effect of ZnO/SnS2 heterojunction, which can enhance the specific surface area and promote the separation of photogenerated electron–hole pairs.