Floating Production Storage and Offloading (FPSOs) are ship-shaped oil and gas processing units capable of operating in various water depths and conditions. As FPSOs collect unprocessed fluids from subsea wells, extract and process oil, water and gas, the risk of explosion due to the handling of these hydrocarbon liquids is very high. To address this, explosion risk analysis is performed to define design accidental loads (blast overpressures) and topside modules shall be checked against blast effect considering these overpressures. The blast analysis can be performed by using linear static analysis and/or nonlinear dynamic analysis. Linear static analysis is very conservative and nonlinear dynamic analysis requires finite element modeling and is time consuming. This paper presents a non-linear pushover analysis method using SACS collapse module to perform the blast analysis in a simplified way. In the proposed method, unit pressure is applied to the structure as uniformly distributed member loads (UDL) in the corresponding directions to represent explosion scenarios. These UDL values are gradually increased until the structure reaches progressive collapse failure to determine the ultimate pressure resistance. The target overpressure is obtained by calculating the dynamic load factor by comparing the natural period of the structure with the pulse duration according to FABIG TN-4 requirements. Finally, the ultimate pressure from pushover analysis is compared with the target overpressure to demonstrate structural integrity of the primary structure of topside module against blast loads. The proposed modeling techniques and analysis method will be very useful and practical in evaluating the explosion risk assessment of FPSO topside modules.