The Longquan Shan fault zone (LQSF) locates in the Sichuan Basin of China, parallel to the well-known Longmen Shan fault zone. Different models for the LQSF indicate different understanding of the geological evolution of the Tibetan Plateau. In this paper, we provide evidences which demonstrate that the LQSF is a normal and deep-buried fault zone. Firstly, we find distinct extensional strains around the LQSF based on Global Positioning System (GPS) observations. We also find that the downward GPS velocities across the LQSF decrease suddenly from 4 to 5 mm/yr at the west to roughly zero at the east. Secondly, we collate focal mechanism solutions to earthquakes of M ≥ 3.0 in the Sichuan Basin and find that 12 out of 21 earthquakes are normal earthquakes. The surrounding extensional strains and the high proportion of normal earthquakes indicate that the shallow part of the LQSF is normal at present. Thirdly, based on the migration section obtained from deep seismic reflection profiling, we outline the geometric structure of the LQSF. It is a deep-buried fault zone that reaches the Moho, with two branches at the top. Such a fault model corresponds with the realities of the low seismic activities around the Longquan Shan anticline, and the scattered earthquakes beneath the Chengdu plain. Finally, we propose a three-stage evolutional model about the Longquan Shan fault system, which includes the formation of anticline in Late Triassic, the uplift of the Mountain in Oligence, and the stage of normal characteristics of the fault zone from Late Miocene.