In the design of long-span spatial steel structures, reasonable selection of the support and upper hanger combination has an important influence on the seismic resistance of the structure. However, such factors are not taken into account in present designs. The main purpose of this paper is to comprehensively select the suitable support and hanger structure for the long-span spatial steel structure, in the hope of better seismic performance. First, three kinds of widely-used contemporary structures were listed. Second, some seismic constraint conditions, such as bearing capacity, stress-strain, and tensile deformation, were presented. Considering seismic constraints, the selection model for the support and hanger with anti-seismic capacity were given along with a concrete calculation example. The support and hanger of long-span spatial steel structure was selected, with a certain seismic capacity considered. The experimental results of the long-span spatial steel structure showed that the seismic level of the core steel structure with the model was obviously improved compared with the traditional random hanger selection method.