The invention discloses a portable full-automatic sunshade installed on a roof of an automobile. The portable full-automatic sunshade installed on the roof of the automobile comprises a sunshade uppercover plate, a sunshade lower cover plate, cover plate lifting elastic pieces, two sets of sunshade rib plane opening and closing mechanisms, two sets of sunshade cloth, a power driving device, a power transmission mechanism and two sets of roof installing transverse rods. According to the portable full-automatic sunshade, the problem that a traditional folding type skeleton structure automobilesunshade has multiple disadvantages is solved, the automobile sunshade can be safely driven along with the automobile in a folded state, and the automobile sunshade does not need to be uninstalled every time, so that the portability of the automobile sunshade is greatly enhanced.