With　the　increasing　integration　of　renewable　energy　sources　represented　by　photovoltaic,　harmonic　issues　can　no　longer　be　neglected.　To　better　describe　the　harmonic　emission　properties　of　photovoltaic　generation　system,　an　equivalent　model　that　can　accurately　calculate　the　output　harmonic　current　of　photovoltaic　generation　system　is　proposed　by　analyzing　the　mechanism　of　harmonic　generation　of　photovoltaic　power.　Aiming　at　the　problem　of　harmonics　generated　by　photovoltaic　modules　and　relevant　control　strategies,　the　harmonic　current　expression　is　constructed　by　analyzing　the　mechanism　of　harmonic　generation.　As　for　the　harmonics　generated　by　the　inverter,　the　expression　of　inverter　harmonic　transfer　function　considering　the　impact　of　external　harmonic　disturbance　and　dead-time　effect　is　established.　The　equivalent　expression　of　photovoltaic　output　harmonic　current　is　derived　so　as　to　establish　a　photovoltaic　power　generation　harmonic　equivalent　model.　Finally,　the　validity　of　the　derived　model　is　verified　by　the　emulation.　©　2023　IEEE.