Abstract: Using LS-DYNA and numerically simulating the explosion in cylindrical reticulated shell, an appropriate model for calculating the dynamic responses of the large-space structure under blast loading was established and the calculations showed a good consistent with J. Henrych’s formulae. The problems of spatiotemporal asynchrony of shock waveforms and pressure distributions on large-space structure surface were solved by extracting the shockwave overpressure data of the finite points on structural surface and using the Proper Orthogonal Decomposition (POD) method. Using Ritz-POD method, the numerical simulation of dynamic responses of large-space single-layer cylindrical reticulated shell under explosion was carried out. The influence of the ratio of rise to span, the height of structure, the TNT equivalence of dynamite and the position of explosion on the dynamic responses of the shell was researched. The numerical simulation results showed that the calculation model is suitable for the dynamic response analysis of the large-space structure under explosion. The maximum displacement and stress responses of the large-space structure under blast loading quickly develop with the increase of the TNT equivalence of explosive, the stress response doubled and the displacement response multiplied. The damages to the large-space structure caused by eccentric blast shock waves are more serious than that caused by central explosion and are most disadvantageous to the edge components of the structure. The more attention should be paid to the anti-explosion capacity of the support areas and edge components for the shells designed by stress control. And in general, the cylindrical reticulated shells with bigger ratios of rise to span are stronger capacity of anti-explosion.