In this study, hierarchical In2S3/Ag3PO4 hybrid photocatalysts were successfully fabricated through an in situ chemical precipitation method and employed to the photocatalytic degradation of methyl orange (MO) under visible light irradiation. As expected, all the In2S3/Ag3PO4 composites exhibited improved photocatalytic activities compared with individual Ag3PO4 and In2S3. Dramatically, the optimal apparent degradation rate constant of the In2S3/Ag3PO4 composite with a theoretical weight content of 4.0% In2S3 was almost 2.3 and 1.6 times higher than that of bare Ag(3)P(O)4 and single In2S3, respectively. The enhanced photocatalytic performance was mainly attributed to the formation of Z-scheme system composed of Ag3PO4, Ag and In2S3, which could not only facilitate the transfer and separation of photogenerated charge carriers, but also preserve a strong oxidation and reduction ability. Furthermore, a reasonable Z-scheme charge transfer mechanism was also proposed in detail.