van der Waals (vdW) layered compounds provided a fruitful research platform for the realization of superconductivity. However, a vdW layered superconductor with a high transition temperature (Tc) at ambient conditions is still rare. Here, using variable-composition evolutionary structure predictions, we systematically explored the stable compounds in the P-S system up to 20 GPa. Opposed to the complex stoichiometries at ambient conditions, only one compound, PS2, is predicted to be thermodynamically stable above 8 GPa. Strikingly, PS2 is a vdW layered material isostructural to 3R-MoS2 exhibiting a predicted Tc of around 11 K at ambient pressure, both in the bulk and the monolayer form. PS2 has been successfully synthesized via high-pressure experiments following the theoretical predictions. This enables replacing transition metals with group V elements in transition-metal dichalcogenides and paves the way in the search for vdW layered materials with superior properties.