This　article　investigates　various　factors　that　may　influence　the　safety　state　of　ancient　timber　architecture,　to　improve　the　accuracy　of　safety-state　evaluation　results　for　ancient　timber　architecture.　During　the　process,　a　safety-state　evaluation　system　for　ancient　timber　architecture　is　developed.　This　safety-state　evaluation　system　includes　five　parts:　foundation,　plinth,　timber　frame,　enclosing　wall,　and　roof.　Based　on　the　system,　a　safety-assessment　model　for　ancient　timber　architecture　based　on　structural　entropy　weight-matter　element　extension　model　is　also　introduced.　In　this　model,　the　structural　entropy　weight　method　is　applied　to　calculating　the　weight　of　each　index　and　takes　the　influence　of　subjective　and　objective　weights　into　consideration　comprehensively.　This　model　has　the　following　three　detailed　steps.　First,　correlation　function　and　correlation　degree　of　extension　set　are　used　to　quantify　the　relationship　between　the　evaluation　indexes　of　the　components,　joints,　and　evaluation　interval　of　each　safety　state.　Second,　the　safety　states　of　units　are　determined　according　to　the　distribution　of　safety　state　of　the　components.　Third,　the　safety　degree　of　the　entire　structure　is　determined　via　the　minimum　safety　state　of　units.　This　study　also　uses　the　Niaoqiangsanchu　in　Forbidden　City　as　a　study　case　and　found　that　the　evaluation　results　are　consistent　with　the　results　of　the　practical　damage　survey　and　the　actual　situation　of　the　architecture.　The　model　thus　minimizes　the　uncertainty　of　qualitative　and　quantitative　factors　in　the　process　of　evaluating　the　safety　degree　of　ancient　timber　architecture,　to　finally　obtain　the　objective　evaluation　results.