The multi-tier rack has multi-tiers of long span shelving racks, it multiplies the utility of the warehouse storage space ad keeping the same features of the long-span shelving. The multi-tier rack can be made either by steel structure platforms and long span rack supported, normally it can be several tiers (commonly 2-3 tiers), with walking stairs, handrails and loading gates, etc. It is best for the high-bay warehouse with small goods, manual picking and big storage capacity with many different types, also goods for old warehouse renewal, it can improve the storage capacity.