The utility model discloses a rain sheltering device of an open storage ground. The rain sheltering device of the open storage ground comprises rain sheltering canvas, a portal, a plurality of operating mechanisms used for supporting and driving the portal, and ladder handrails arranged on the portal. The rain sheltering canvas is provided with hanging rings, the portal is provided with two sets of electric hoists which are distributed in rows, and lifting hooks on the electric hoists are connected with the hanging rings. By the adoption of the rain sheltering device of the open storage ground, the electric hoists on the portal can pull the rain sheltering canvas to cover the storage ground, a goods heap is directly used for supporting the rain sheltering canvas and suffering from wind loads, rain and the like, the amount of labor and the labor force investment are greatly lowered, and safety is high. Meanwhile, the operating mechanisms are used for achieving rapid ground transformation, one portal can be used in a plurality of storage yards, and the rain sheltering device of the open storage ground is convenient to operate, high in university and widely applicable to the open storage ground of materials such as grains.