•Fretting-fatigue failure initiates micro cracks at the trailing edges induced by mixed slip regime.•Larger fretting amplitude induces larger tangential force and friction, but smaller fatigue life.•Fretting scar depth increases as fretting-fatigue proceeds while its growth rate reduces greatly.•Larger fretting amplitude (normal force) makes mixed slip regime great (materials brittler).•Relative sliding and contact stresses can lead to fretting-fatigue failure of bridge cables. Bridge cables are subjected to small relative sliding and high contact stresses among wires under fluctuating loads and repeated bending, eventually leading to fretting-fatigue failure. This paper presents a series of fretting fatigue tests with different fretting and fatigue parameters to investigate the tribological properties, fretting fatigue characteristics and fracture failure mechanism. Results show that the fretting-fatigue failure evolved from surface micro cracks at the trailing edges generated from a mixed slip regime. Larger fretting amplitude induced larger tangential force and coefficient of friction, and decreased life. Fretting scar depth increased as fretting-fatigue proceeded while the growth rate was declining.