From　the　source-load　perspective,　considering　the　safety　operation　constraints　of　grid　dispatching,　a　dispatching　model　that　takes　into　account　flexible　load　demand　response　and　power　system　flexibility　is　established.　Based　on　the　price-based　demand　response　and　highly　flexible　load　model,　the　flexible　load　demand　response　model　is　built　to　respond　to　the　level　of　wind-photovoltaic　output,　guide　load-side　users　to　change　their　power　consumption　behavior,　regulate　the　demand　for　power　system　flexibility　and　improve　the　consumption　rate　of　new　energy.　Based　on　the　supply-demand　balance　mechanism　of　power　system　flexibility　and　the　uncertainty　of　wind-photovoltaic　output　and　load,　we　construct　power　system　flexibility　indexes　in　different　time　scales,　combine　with　the　comprehensive　economic　cost　index　of　grid　operation,　consider　source-load　coordination,　design　joint　optimal　dispatching　strategy,　and　generate　typical　scenarios　based　on　improved　deep　embedding　clustering　algorithm　to　establish　optimal　dispatching　model,　so　as　to　reduce　the　influence　of　uncertainty　of　wind-photovoltaic　output　and　load　demand　on　the　optimization　results.　The　uncertainty　of　wind-photovoltaic　output　and　load　demand　can　reduce　the　impact　on　the　optimization　results.　Finally,　the　feasibility　and　rationality　of　the　proposed　model　are　verified　by　an　example　analysis　of　a　regional　power　grid.　©　2022　IEEE.