In the last ten years, bismuth oxybromide (BiOBr) has attracted wide attention due to its superior optoelectronic property. However, its practical application still suffers from slow carrier transport and high carrier recombination. Here we report a kind of novel tannum indium sulfide (SnIn4S8)/BiOBr hybrid prepared by a two-step hydrothermal method. The results showed that small amount of SnIn4S8 had no influence on the crystal phase of BiOBr, but the morphology could be regulated from nanosheet to nanoflower. Specially, SnIn4S8 exerted a slight effect on the light absorption and band gap of BiOBr. Importantly, SnIn4S8/BiOBr hybrids exhibited remarkable enhancement of the photocatalytic activity towards the degradation of rhodamin B (RhB) dye molecules. SnIn4S8/BiOBr-0.20 with 99.8% degradation efficiency had the highest photocatalytic activity within 40 min, while it was only 71.1% for pure BiOBr. The enhanced photocatalytic activity was mainly attributed to efficient interfacial transfer and low carrier recombination. This work will help us understand the photocatalytic mechanism of bismuth oxyhalide hybrids.