The invention provides a static crossing device and a flange assembly. The static crossing device comprises a crossing sheet and a bracket, wherein the crossing sheet comprises a first side sheet and a second side sheet which are oppositely arranged and electrically connected; a first compressing part for compressing the first side sheet is arranged on the bracket, and a second compressing part for compressing the second side sheet; the first side sheet and the second side sheet of the crossing sheet are oppositely close through the first compressing part and the second compressing part, so that the first side sheet and the second side sheet are in close contact with two sides of a device requiring static crossing; the static crossing function of the static crossing device can be achieved through the first side sheet and the second side sheet which are electrically connected, and thus the electric crossing is hardly failed; when the static crossing device is mounted on the device requiring static crossing, the device requiring the static crossing is arranged between the first side sheet and the second side sheet of the crossing sheet, and any spare part in the device requiring the static crossing is not dismounted, so that the convenience of mounting is ensured.