The utility model discloses a wind-proof mechanism for trackless telescopic door, consisting of a wind-proof plate and a wind-proof track. The wind-proof plate is fixed on a lower horizontal frame of the door body. A groove with hooked edge is positioned on the lower part of the wind-proof plate, and a convex edge is arranged on the top of the wind-proof track, wherein, the convex edge is arranged in the hook side groove of the lower wind-proof plate. As the groove with hooked edge of the lower wind-proof can match with the I-shaped convex edge of the upper wind-proof track, when the door body meets wind, the lower convex edge of the wind-proof plate hooks the wind-proof track, thus the upper convex edge prevents the door body form inclining and effectively solving the problem that the door body is blew down by the wind.