The invention relates to a storage inner cavity adjustable cup holder. The storage inner cavity adjustable cup holder comprises a cup holder body; a storage inner cavity for storage is embedded in the cup holder body; the storage inner cavity adjustable cup holder also comprises a plurality of partitions; the partitions are movably arranged in the storage inner cavity; slide rails parallel to the inner bottom surface of the storage inner cavity are embedded in two side walls of the storage inner cavity; two side walls of the partitions are provided with sliders corresponding to the slide rails; the sliders are matched with the slide rails in a sliding manner; clamping grooves are embedded in two side walls at upper ends of the partitions; U-shaped elastic rubber pads are clamped in the clamping grooves; the length of each of the U-shaped elastic rubber pads is greater than a space between the inner side wall of the clamping groove in the upper end of each partition and the side wall of the storage inner cavity. The storage inner cavity adjustable cup holder is high in adaptability, and the storage space is convenient to adjust according to the size of an article to be stored.