The invention discloses a sun roller blind device for car skylight which is added with a guiding passage with a deformation part base on technical wrap-up device. The deformation part can guide a strength belts on both sides of the roller blind clothing to deform and then go into the matching track, the strength belts can be trued over and separated from the bottom roller blind, so that The slide in the guideway being not smooth and inadequate strength of the edge are of the roller blind are avoided.