The utility model provides a cabinet base bracket. The cabinet base bracket is provided with four bracket bases. Each bracket base is composed of an upper bracket and a lower bracket. The middles of the lower ends of the three side faces of each upper bracket are respectively provided with a bolt groove used for fixing the corresponding upper bracket. The middles of the three side faces of each low bracket are respectively provided with a rectangular groove. The bracket bases are connected through cross arms in a welded mode. Two ground mounting grooves are formed underneath the bracket bases. The cross arms are provided with cross arm extension rods in a nested mode, and the cross arm extension rods can be stretched from 200mm long to 600mm long. Every two adjacent bracket bases are respectively welded to the cross arms. The cross arm extension rods are fixed to the cross arms through fixing bolts. The height of the cabinet base bracket can be adjusted, and meanwhile length and width of the overall bracket can be changed at will within a stated size through the cross arm extension rods of the cross arms connected between every two adjacent bracket bases. In this way, the problem that the reserved position for I-steel in a computer room is insufficient is solved, so that a workload is relieved, and time is saved.