Lunar lava tubes, formed by volcanic activity, present potential habitats for future human exploration due to their stable environments. This research uses a 3D inversion technique to detect these tubes by analyzing gravity anomalies from NASA's GRAIL mission. Four potential regions were modeled, with two main candidates located at Schröter extension and Rima Mairan. These models reveal extensive underground networks, with the Schröter extension tube spanning 63 km and the Rima Mairan tube extending 160 km. The study's 3D models, enhanced by LRO topographical data, provide critical insights for future lunar exploration and habitation planning.