The fault geometry and the regional tectonic stress field form the basis for studying scientific issues such as crustal deformation and earthquake generation environments. This paper examines the fault structure and stress state of the seismic source region for the M_W7.8 and M_W7.6 earthquakes in Turkey on February 6, 2023. Based on fault distribution characteristics and the spatial distribution of focal mechanism solutions, the M_W7.8 main shock was divided into the Pazarcik segment and the Naril segment for study, while the M_W7.6 main shock was divided into the Savrun segment and the Çardak segment. For each segment, a clustering nodal planes analysis of focal mechanism solutions and an inversion of the stress field in the seismic source region were carried out, determining the seismic structural parameters and the tectonic stress field for the doublet earthquake sequence. The research findings are summarized as follows: (1) Based on the clustering of focal mechanism solutions, the strike and dip angles of the seismic fault in the Pazarcik segment of the M_W7.8 earthquake are 56.2° and 85.8°, respectively; while in the Naril segment, the strike and dip angles are 39.7° and 85.2°, respectively. (2) For the Savrun segment of the M_W7.6 earthquake, the strike is 75.3° with a dip angel of 82.1°. The strike and dip angles of the Çardak segment are 265.3° and 85.9°, respectively. (3) The stress field inversion results indicate that the stress field in the source region of the M_W7.8 earthquake is complex, with regimes including strike-slip, normal faulting, and oblique-slip. On the Narli and Pazarcik segments, the stress field is strike-slip faulting stress regime, with the principal compressive stress axis of the Narli fault trending NNW-SSE and the Pazarcik segment's principal compressive stress axis trending nearly N-S, consistent with the dominant strike-slip movement of the East Anatolian Fault. From the Narli fault to the Amanos fault segment, the stress field transitions from strike-slip faulting to a combination of normal faulting and strike-slip, and then to a normal faulting stress field at the Amanos segment. (4) The overall orientation of the principal compressive stress axis of the M_W7.6 earthquake is NNE-SSW, and the orientation of the principal tensile stress axis is NWW-SEE. The Savrun segment of the M_W7.6 earthquake is dominated by tensional stress, while the Çardak segment is dominated by strike-slip faulting stress regime.