1. Different connection joint: The nodes of the space frame structure are regarded as hinged connections and are usually connected by bolts. Portal steel structure joints are regarded as rigid joints and usually welded.

2. The structural system is different: the space frame is a spatial structural system, and the overall force and spatial deformation should be considered when calculating. The steel structure truss is similar to the plane steel truss, which belongs to the unidirectional force structure. As long as the in-plane strength and stability are calculated, the out-of-plane stability mainly depends on the brace and tie rods.

3. Different materials and forms: the grid can have steel grids, aluminum alloy grids, etc., but steel grids are mostly used in practical applications. In addition to steel space frame, there are steel frames, steel door frames, etc. Many forms.