In　the　process　of　unmanned　aerial　vehicle　(UAV)　visual-navigation-algorithm　design　and　accuracy　verification,　the　question　of　how　to　develop　a　high-precision　and　high-reliability　semi-physical　simulation　platform　has　become　a　significant　engineering　problem.　In　this　study,　a　new　UAV　semi-physical-simulation-platform　architecture　is　proposed,　which　includes　a　six-degree-of-freedom　mechanical　structure,　a　real-time　control　system　and　real-time　animation-simulation　software.　The　mechanical　structure　can　realistically　simulate　the　flight　attitude　of　a　UAV　in　a　three-dimensional　space　of　4　x　2　x　1.4　m.　Based　on　the　designed　mechanical　structure　and　its　dynamics,　the　control　system　and　the　UAV　real-time　flight-animation　simulation　were　designed.　Compared　with　the　conventional　simulation　system,　this　system　enables　real-time　flight-attitude　simulation　in　a　real　physical　environment　and　simultaneous　flight-attitude　simulation　in　virtual-animation　space.　The　test　results　show　that　the　repeated　positioning　accuracy　of　the　three-axis　rotary　table　reaches　0.006　degrees,　the　repeated　positioning　accuracy　of　the　three-axis　translation　table　reaches　0.033　mm,　and　the　dynamic-positioning　accuracy　reaches　0.04　degrees　and　0.4　mm,　which　meets　the　simulation　requirements　of　high-precision　visual　UAV　navigation.