The　mechanism　of　healing　fatigue　damage　was　investigated　by　pulsed　laser　surface　irradiation　for　polycrystalline　copper　film,　X-ray　Diffraction(XRD),　optical　microscopic.　The　results　indicate　that　surface　melting　and　grain　refinement　were　found　in　the　melted　surface　layer.　Tensile　residual　stresses　were　introduced　in　the　resolidified　surface　layer　due　to　laser　surface　melting　which　produced　deleterious　effect　on　fatigue　properties.　Remelting　and　grain　refinement　in　the　surface　layer　is　mainly　responsible　for　healing　fatigue　damage　and　fatigue　life　improvement.　The　fatigue　damage　could　be　healed　completely　or　partly　by　laser　surface　irradiation　under　the　proper　parameters　of　laser　treatment　for　the　specimens.