<p>Transmission tower-line systems (TTLSs) play a crucial role in the long-distance transmission of electrical energy, often necessitating their crossing through active fault areas. However, previous studies have given limited attention to the seismic performance of fault-crossing transmission TTLSs, particularly in terms of considering the impact of permanent ground motion displacements (PGMDs). This study attempts to address this concern by evaluating the seismic performance of TTLSs exposed to fault earthquakes. Three strike-slip ground motions are carefully selected, and the corresponding PGMDs are accurately replicated through baseline adjustment. A meticulously designed and fabricated reduced-scale experimental model of a TTLS is then employed to investigate the influence of the fault crossing location (FCL) on its seismic performance. The shake table tests conducted unequivocally demonstrate that PGMDs significantly amplify the seismic responses of the TTLS and identify the most unfavorable FCL. Furthermore, a finite element model (FEM) is developed and its accuracy is validated by comparing it with the experimental results. Parametric analyses are conducted to explore the effects of fault crossing angles (FCAs) and PGMD amplitudes on the seismic performances of TTLSs. This study is expected to contribute valuable insights for the seismic design and performance analysis of TTLSs crossing fault areas.</p>