In recent years, the global gravity model EIGEN-6C4 has been evaluated as one of the modern global gravity models with high resolution and accuracy thanks to the combination of satellite and ground data. This study uses different technical maps of Bouguer gravity anomaly data of the north of the Paracel Islands to contribute to a better understanding of the geological structure and tectonic faults. The modern edge detection techniques were tested on a synthetic model before being applied to the gravity data of the Paracel islands. The obtained structural map from the real model aligns with the primary fault system of the study area, which extends in multiple directions including NE–SW, NW–SE, WSW-ENE, WNW-ESE, and NNW-SSE. These orientations often represent the distribution and orientation of islands, reefs, and coral atolls; playing an important role in elucidating the geological structure of the study area and providing useful information about the study area's rich resources.