We　propose　a　protocol　for　implementing　phase　gate　of　two　photons　with　linear　optical　elements　and　an　atom-cavity　system.　The　evolution　of　the　atom-cavity　system　is　based　on　the　quantum　Zeno　dynamics.　The　devices　in　the　present　protocol　are　simple　and　feasible　with　current　experimental　technology.　Moreover,　the　method　we　proposed　here　is　deterministic　with　a　high　fidelity.　Numerical　simulation　shows　that　the　evolution　in　cavity　is　efficient　and　robust.　Therefore,　the　protocol　may　be　helpful　for　quantum　computation　field.