The foldable storage cage has a uniform capacity and fixed spec, suited to irregular materials and dense storage of large batches. It stacks itself to use space fully, folds flat when idle, and fits integrated logistics handling. Storage cages can also be designed and built to customer requirements. Structural features of the foldable storage cage: 1. Neat storage, easy fixed-position and unitized management; 2. Stacks four layers high for three-dimensional storage; depending on model and spec, each cage carries between 0.8T and 2.5T; 3. Empty cages fold flat when not in use, saving space; 4. Suited to loading, moving, and stacking by forklifts, cranes, overhead traveling cranes, lifts, trolleys, and hand pallet trucks, saving time and labor; 5. The cage door opens, so needed material can be taken without unpacking the whole stack; 6. Spot-welded from strong steel bars with a U-channel-steel-reinforced bottom for a sturdier structure; 7. Simple to operate, widely applicable, and long-lasting.