The Loess Plateau region is prone to frequent strong earthquakes， which often trigger large-scale， intensive loess landslides. Shallow buried bias loess tunnels are highly susceptible to significant seismic damage due to factors such as thin overburden and unsupported slope faces， which result in pronounced seismic amplification effects. The seismic damage characteristics and mechanisms of shallow buried bias large section loess tunnels were systematically investigated through large-scale shaking table model tests. The results indicate that the presence of tunnel cavities significantly influences the distribution characteristics of acceleration amplification factors on the slope face， with the main affected region being between 0.25H and 0.80H. The horizontal acceleration amplification factor within the slope increases nonlinearly with elevation， with weaker amplification effects below approximately 2/3 of the slope height and significantly stronger amplification effects above approximately 2/3 of the slope height. Under horizontal seismic loading， the tunnel lining experiences extensive tensile and compressive through-cracks along the conjugate 45° directions from the right arch waist to the left wall foot， and from the left arch waist to the right wall foot， resulting in severe seismic damage. Under the condition of small-angle bias， continuous slip surfaces extend from the slope crest to the tunnel’s deep-buried side wall foot， with local continuous sliding and localized collapse occurring at the slope surface and crest. The dynamic amplification effect of the tunnel cavities is the primary cause of the formation of local slip surfaces at the slope surface， while the combined shear force from the seismic inertia force and gravitational force of the rock-soil body is the fundamental cause of the inward deformation of the tunnel lining on the deep-buried side and outward deformation on the shallow side. The findings of this study provide valuable insights into the seismic design of shallow buried bias loess tunnels.