The invention relates to a welding ball net rack unit splicing device and method. The welding ball net rack unit splicing device comprises an upright tube standard section, an upright rod height adjusting section, a horizontal rod angle adjusting section and an embedded part which are fixedly connected from top to bottom in sequence; several horizontal rods with angles are movably installed on thehorizontal rod angle adjusting section, and each horizontal rod is provided with a horizontal rod sliding fixed support or a horizontal rod sliding adjustable support. By means of the welding ball net rack unit splicing device and method, the entirety splicing method of a net rack is changed into a unit splicing form from a loose item splicing form, and the purposes of increasing the overall splicing speed and improving the overall splicing precision of the net rack are achieved.