The utility model discloses a ladder beam angle adjusting device, connect the gear that sets up between casing and first connection casing and the second connection casing including first connecting seat, second connecting seat, first connection casing, the second of gomphosis on the second connecting seat of gomphosis on first connecting seat of two relative settings, gear top end inlays the formula meshing with the first casing bottom end tooth of being connected, and the meshing of casing ring gear is connected with the second in the gear outer lane. The utility model discloses a rotate first connecting seat or second connecting seat, can adjust the angle between first connecting seat and the second connecting seat, and first connecting seat and second connecting seat and ladder beam end connection, can reach two sections ladder beam angular adjustment's of mutual butt joint mesh to the landing of the different angles of satisfying the demand carries out the operation requirement of being under construction.