Novel golf-ball-like polystyrene (PS) microspheres were obtained through gamma-ray-radiation-initiated polymerization of styrene (St) monomers in a Pickering emulsion stabilized by amphiphilic snowman-like PS Janus microspheres, which were synthesized via seed emulsion polymerization of St swollen in poly(acrylic acid)-functionalized crosslinked PS (PA-CPS) seed microspheres. It was found that the stability of the Pickering emulsion and the hole size of the golf-ball-like PS microspheres depend on the geometry of the amphiphilic snowman-like PS Janus microspheres, which can be tuned by the weight ratio of the styrene monomer to PA-CPS seed microspheres (WS-CPS). This work provides a simple strategy to synthesize amphiplailic Janus microspheres and opens a new way to prepare polymer microspheres with holes on the surface.