The invention relates to a fixing support assembly of an automobile storage battery. The fixing support assembly of the automobile storage battery comprises a lower support, an upper support and two boss components. The fixing support assembly of the automobile storage battery is characterized in that an inclined plane which tilts towards the left is arranged on the lower support, and a first mounting hole is formed in the right end of the inclined plane; a second mounting hole and a third mounting hole are formed in the edge of the front side and the edge of the rear side of the lower support; a fourth mounting hole and a fifth mounting hole are formed in the front portion and the rear portion of the right side of the lower support; the left portion of the upper support is connected with the two boss components, two protrusions are arranged on the right side of the upper support, and the two protrusions and the boss components are respectively provided with a via hole; a through hole corresponding to the first mounting hole is formed in the middle of the right side of the upper support; the upper support and the lower support are fixedly connected to form a cavity structure. The fixing support assembly of the automobile storage battery mainly solves the problems that the mounting space for transverse arrangement of a 19.4kg storage battery is narrow and small, and rigidity and intensity are low.