To improve the lubrication performance of line contact pairs such as gears and cylindrical roller bearings,it is necessary to investigate the effects of oil-supply conditions on their mixed lubrication characteristics. Based on the average flow model,a line contact non-Newtonian thermal mixed lubrication model was established by considering oil supply conditions. Taking the inlet oil supply quantity as the parameter to control the degree of starvation,and by simultaneously considering the film thickness ratio (the ratio of minimum film thickness to roughness) and the rough peak contact load ratio (the ratio of rough peak contact load to total load) to judge the lubrication state,the effects of oil supply quantity,velocity,contact pair materials and ambient viscosity on mixed lubrication performance were studied. The results show that,with the increase of oil supply quantity,the film thickness ratio increases,the asperity contact load ratio decreases,the minimum and central film thickness increase gradually,the average friction coefficient decreases,and the maximum film temperature increases gradually. However,they tend to a stable value finally. For three different contact pairs (steel-steel,steel-Si3N4 and Si3N4-Si3N4),the total pressure and oil film temperature of steel-steel contact pair are the lowest,and the total pressure and oil film temperature of Si3N4-Si3N4 contact pair are the highest. Under the fully flooded condition,the film thickness of Si3N4-Si3N4 contact pair is higher slightly,the film thickness ratio is the highest,and the asperity contact load ratio is the lowest. Under the starved condition,the film thickness of the steel-steel contact pair is thicker slightly,the film thickness ratio is the highest,and the asperity contact load ratio is the lowest. With the increase of velocity or ambient viscosity,the film thickness increases,the total pressure remains unchanged,the asperity pressure decreases,the film thickness ratio increases and the asperity contact load ratio decreases. Different from fully flooded condition,the mixed lubrication performance is poor under the starved condition.