In　this　paper,　based　on　the　problem　of　poor　operation　of　sweet　potato　harvester,　the　discrete　element　method　and　TRIZ　theory　are　used　to　optimize　the　key　mechanism.　Based　on　the　discrete　element　method,　EDEM　software　was　used　to　simulate　the　operation　process　of　the　potato　soil　conveying　and　separating　mechanism,　and　the　optimal　combination　of　working　parameters　was　obtained.　The　linear　velocity　of　the　rod　lift　was　2.3　m/s,　the　inclination　angle　was　18　degrees,　and　the　amplitude　was　8　mm.　Field　experiments　were　carried　out　to　verify　the　results.　Through　the　problems　in　simulation　and　field　experiment,　based　on　TRIZ　theory,　the　improvement　scheme　is　proposed　by　using　physical　contradiction,　and　the　two-stage　potato　soil　transport　separation　mechanism　is　obtained.　The　simulation　results　show　that　the　operation　effect　is　improved　obviously.　Finally,　the　optimization　of　potato　soil　transport　and　separation　mechanism　is　completed　by　determining　the　optimal　working　parameters　and　improving　the　structure　innovation.