To provide a cargo collapse prevention device which prevents cargo from collapsing effectively even if the height of the cargo varies substantially, while keeping expansion bodies away from the way of loading/unloading or moving of the cargo.

The cargo collapse prevention device consists of expansion bodies B provided in a cargo storing space (r), and an air supply/discharge mechanism freely supplying air to the expansion bodies B to expand them for limiting or preventing the movement of the cargo. A plurality of subdivided expansion bodies 17 are connected in series in a state where internal spaces are communicated with each other, thereby forming the expansion bodies B into bellows expansion bodies. The bellows expansion bodies B are configured to be freely switchable between a use condition where the subdivided expansion bodies 17 are elongated in the series connection direction while being expanded by air supply, and a non-use condition where the subdivided expansion bodies 17 are shortened in the series connection direction while being contracted by air discharge.