By use of SAP2000,five kinds of chessboard-shaped pyramid space grid which span in 64～96 meters were made as examples for modeling,which were compared with the mechanical properties.The results show that the natural vibration period is related to span and load rating of the space grid.The internal force distribution regulation under the combination of static load and vertical earthquake were also decrypted that the tension of upper chord was transited to the central pressure from surrounding;the maximum internal force of bottom chord occurred in the one force plane central;and the maximum internal forces of belly bars occurred in the surrounding pyramids,which was available for design and engineering project.