The Baekdu Volcano is located on the border between Jilin Province, China, and Ryanggang Province, North Korea. Its 946 AD eruption had a Volcanic Explosivity Index (VEI) of 7, making it among the most massive eruptions in the past 2000 years, a “Millennium eruption”. Mount Baekdu may erupt in the near future. To examine the future impact of Mount Baekdu, we generated a synthetic interferogram using a Mogi model equation to produce a simulated surface deformation phase and added simulated orbital error, topographic error, and atmospheric effects phases. We output the simulation results to the program LAHARZ, which can generate a potential hazard zone due to lahar flow. Using LAHARZ, the area affected by a Baekdu lava flow would be 4.575, 14.522, 15.866, 60.351, 404.848, 3,019.298, and 6,001.885 km² with a VEI scale eruption of 1 to 7, respectively, while the synthetic interferogram showed that the simulated surface deformation at Mount Baekdu would be 0.04 cm, 0.1 cm, 0.7 cm, 10 cm, 1 m, 12 m, and 100 m according to the VEI category. This study can be used to estimate the interferometric synthetic aperture radar (SAR) surface deformation of Mount Baekdu and produce a hazard inundation zone map with a more certain lahar flow volume in an actual volcanic eruption and surface deformation detected using SAR images on inflation of the magma chamber.