This article focuses on the research of seismic response character of common space truss under the impact of the pulse-type ground motion, and some meaningful results listed below have been obtained: (1) In order to apply the method in the construction designing, a simplified spring-mass-damping system is put forward through the theoretical derivation and numerical simulation, which could consider the effects of bending and shearing. This system can replace the supporting structures and participate in the coupling reaction with space truss. (2) The character of near fault large pulse-type ground motion is simply explained. The differences of the seismic response are compared between the pulse-type ground motions and the non-pulse-type ground motion of the peak (0.10g) acting on the same space truss. The correlation of the big pulse velocity spectrum and structure natural period of structure response is discussed. (3) The responses of the simplified model and the actual model under the impact of the ground motions are analyzed and compared. The result shows the reasonableness and accuracy of the simplified model. The research could provide a scientific and simplified model for the designers.