Abstract: Following an explosion accident, a public safety explosion accident analysis method based on open-source information fusion was proposed to quickly and accurately assess the scope and severity of the accident's impact and to formulate a scientific and reasonable emergency response strategy. Furthermore, regarding the May 27 chemical plant explosion accident in Gaomi, Shandong, a logical chain for accident analysis was rapidly constructed. Specifically, open-source information was used to obtain critical details such as the explosion generation, the shockwaves propagation, and structural damage to buildings in both the plant area and far field. Based on criteria for structural damage and the laws of shockwave propagation, the explosion source location and explosive equivalent were reverse-calculated, and the cause of the accident was analyzed. Numerical simulations provided key evidence for improving safety protection in industrial plants. The results indicate that the explosion source was located at the No. 1 nitration device, with an explosive equivalent of approximately 12 tons of TNT, consistent with the conclusion based on field investigation, thereby verifying the effectiveness and accuracy of the new method. The main causes of the accident were identified as the company's actual production load exceeding design standards, prolonged operation of equipment under full load conditions, and long-term neglect of the safety interlock system. Installing protective structures around explosion-prone equipment or structures can effectively attenuate the shockwave load propagated to adjacent building surfaces, reduce the damage level, and narrow the destruction scope. The proposal of this new method provides a novel approach to the existing accident investigation system, effectively enriches investigation techniques, and demonstrates the necessity for continued research and practical value.