Gravity　expansion　foundation　is　the　primary　form　of　onshore　wind　turbine　foundations.　Because　the　prefabricated　foundation　is　a　developing　trend　for　wind　power　structure　system,　assembly　foundation　with　combinations　of　key-tooth　joints　and　prestressing　dry　connections　is　proposed　for　onshore　wind　turbine　system　in　this　paper.　To　examine　the　mechanical　performance　and　effect　factors　of　this　newprefabricated　foundation　structure,　the　stability　and　load-bearing　capacity　of　typical　prefabricated　foundation　structures　are　analyzed.　Structural　response　characteristic　values　of　prefabricated　foundation　structures,　including　foundation　void　ratio,　steel　bar　stress　levels,　and　concrete　compressive　stress,　are　analyzed.　The　results　showthat　the　reinforcement　of　shear　key　construction　is　the　controlling　factor　in　the　stress　calculation　of　steel　bars　in　prefabricated　foundation　structures.