In　this　work,　we　extend　the　well-known　Melnikov　method　for　smooth　systems　to　a　class　of　planar　hybrid　piecewise-smooth　systems,　defined　in　three　zones　separated　by　two　switching　manifolds　and　.　We　suppose　that　the　dynamic　in　each　zone　is　governed　by　a　smooth　system.　When　a　trajectory　reaches　the　switching　manifolds,　then　reset　maps　describing　impacting　rules　on　the　switching　manifolds　will　be　applied　instantaneously　before　the　trajectory　enters　into　the　other　zone.　We　also　assume　that　the　unperturbed　system　is　a　piecewise-defined　continuous　Hamiltonian　system　and　possesses　a　pair　of　heteroclinic　orbits　transversally　crossing　the　switching　manifolds.　Then,　we　study　the　persistence　of　the　heteroclinic　orbits　under　a　non-autonomous　periodic　perturbation　and　the　reset　maps.　In　order　to　obtain　this　objective,　we　derive　a　Melnikov-type　function　by　using　the　Hamiltonian　function　to　measure　the　distance　of　the　perturbed　stable　and　unstable　manifolds　in　this　system.　Finally,　we　employ　the　obtained　Melnikov-type　function　to　study　the　persistence　of　a　heteroclinic　cycle　and　complicated　dynamics　near　the　heteroclinic　cycle　for　a　concrete　planar　piecewise-smooth　system.