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In this paper,dynamic caustic method is applied to analyze the blast-induced crack propagation and distribution of the dynamic stress field around an empty circular hole in polymethyl methacrylate (PMMA) material under delayed ignition blasting loads.The following experimental results are obtained.① In directional-fracture-controlled blasting,the dynamic stress intensity factors (DSIFs) and the propagation paths of the blast-induced cracks are obviously influenced by the delayed ignition.② The circular hole situated between the two boreholes poses a strong guiding effect on the coelesence of the cracks,causing them to propagate towards each other when cracks are reaching the circular hole area.③ Blast-induced cracks are not initiated preferentially because of the superimposed effect from the explosive stress waves on the cracking area.④ By using the scanning electron microscopy (SEM) method,it is verified that the roughness of crack surfaces changes along the crack propagation paths.