The invention belongs to the technical field of steel structure buildings, and particularly relates to a funnel type sand box unloading device and method which are used for unloading temporary supporting frames of bearing steel components. Four bolts in a horizontal release part need to be unscrewed before unloading is started, and horizontal displacement of the steel components in the unloading process is effectively released through sliding between a stainless steel plate and a slide plate. The unloading device is novel in concept, can conveniently unload the temporary supporting frames of the steel structure, and has the advantages of being good in sealing performance, capable of releasing horizontal displacement of supporting points, convenient to operate, high in safety, and the like.