The invention discloses a steel ball press-in machine for a universal wheel of luggage. The steel ball press-in machine structurally comprises a press-in support rod, a press-in device, an air pump motor, a pressurizing air pump, a funnel assembling rod, a steel ball funnel, a rotating ring, a steel ball connecting pipe, a universal wheel placing table, a placing supporting rod and a main machinetable; the main machine table is a cuboid, the press-in support rod is vertically welded to the middle part of the left side of the top end of the main machine table, the press-in support rod is a cuboid, and the top end of the press-in support rod is vertically welded to the middle part of the left side of the bottom end of the press-in device; the placing supporting rod is a cylinder, the bottomend of the placing supporting rod is vertically connected with the main machine table in a locking mode, the universal wheel placing table is vertically welded at the top end of the placing supporting rod, and the universal wheel placing table is located at the right side of the pressing-in support rod. According to the steel ball press-in machine, when a user uses the machine, automatic fallingpositioning of the machine and press-in of balls can be realized only by controlling pressure pumping and charging of the machine, through an ejector rod and springs in a positioning plate, a pressingrod can be unlocked to press the steel balls only when the pressing rod is positioned to the point so that the steel balls can be prevented from being pressed and falling down in advance, and therefore empty pressing can be prevented, safety of the machine is guaranteed, and the machine is convenient to use.