Zeolitic imidazolate framworks-8 (ZIF-8) and two-dimensional black phosphorus (BP) are frequently studied for their outstanding properties and wide applications. Therefore, integrating these two components into hybrid nanocomposites is conceivable to build a hybrid nanomaterial with enhanced or even new properties. In this paper, a novel hybrid nanocomposite of ZIF-8 with few-layer two-dimensional (FL-BP) (ZIF-8/BP) is prepared for the first time. The obtained ZIF-8/BP hybrid composites are composed of ZIF-8 nanoparticles uniformly distributed over the whole BP nanosheets. The in situ growth of ZIF-8 is attributed to FL-BP functionalized with polyvinylpyrrolidone (PVP), whose pyrrolidone rings (CO) enhance the affinity between Zn ions and FL-BP, and in turn facilitate ZIF-8 in situ growth on the surface of BP. Furthermore, the obtained ZIF-8/BP hybrid nanocomposites demonstrate enhanced photocatalytic performance, for the highly efficient charge separation and transfer during photocatalytic reactions.