Two models are compared for calculating the surface separation in a multiscale elastohydrodynamic lubricated line contact for the same operating conditions. In the studied line contact, the surface separation is very low so that the effect of the adsorbed boundary layer is significant. Model I principally takes the continuum fluid film as intervening between the two adsorbed boundary layers. Model II takes the continuous phase transition both along the flow direction and across the whole surface separation; in this model, in the Hertzian contact zone there is only the adsorbed boundary layer, while in most of the inlet zone there is only the continuum fluid film (by neglecting the adsorbed boundary layer). The analytical results show that for the same case these two models give the close surface separations. The equivalence of these two models is shown.