Abstract: The damages such as cracking and bending deformation in the timber beam-column joints in traditional vernacular dwellings in the Xianshui River Basin of Garzê Tibetan Autonomous Prefecture， Sichuan Province， the normal use of the house is affected， posing safety risks such as fracture of the main joint. Based on the survey data of Diqingyi Village in the upper Xianshui River Basin， this study takes the typical beam-column joint of a timber-framed house in the village as the research object. A steel reinforcement component was designed to address these issues. Finite element analysis software was used to establish models of the joint and the steel component， analyzing the failure conditions of the joint before and after reinforcement. Three performance indicators of the joint—hysteresis curve， skeleton curve， and stiffness degradation curve—were compared to evaluate the effectiveness of the reinforcement. The results indicated a 69.19% reduction in maximum von Mises stress （from 6.127 MPa to 1.888 MPa） following reinforcement. The bearing capacity increased by 35.52% to -25.45 kN at -120 mm displacement and by 25.60% to 28.89 kN at +150 mm displacement. The reinforced joint demonstrated improved stability， enhanced energy dissipation capacity， and greater deformation resistance under cyclic loading， confirming the system's effectiveness in seismic risk mitigation.