The utility model relates to a scroll casing of a wind curtain machine, which comprises a scroll casing body, a through-hole and a removable cover board positioned on the front of the scroll casing body, and a built-in front edge processed at the periphery of the cover board. The height of the built-in front edge is equal to the thickness of the wall of the through-hole; steps are arraned at the periphery of the through-hole; an insertion head of a screwdriver is positioned between the cover board and the shell body; when in operation, the cover board and the shell body can be fixed with each other by screwing tight a screw; when in maintenance, the screwdriver is used for unscrewing the screw, the cover board is turned up, and a brush is directly inserted into the through hole to clean a wind wheel at the prior suspending position of the wind curtain machine directly, so that the labor cost for maintenance is simplified and saved, therefore, the scroll casing is applied to be used in various wind curtain machines.