The invention provides a COB (Chip On Board) automatic sorting unit, relating to an automatic chip testing device. The automatic sorting unit comprises a central control system, an input cassette system, a driving unit, a testing feed track and an output cassette system, wherein the input cassette system, the driving unit, the testing feed track and the output cassette system are respectively connected with the central control system. The input cassette system is positioned on one end of the testing feed track, and comprises a cassette system track, a locating rack, a feed bowl stand perpendicular to the locating rack, and an input cassette feed bowl vertically arranged on the feed bowl stand, wherein the input cassette feed bowl is provided with a plurality of input trenches. The output cassette system is positioned on the other end of the testing feed track, and comprises a cassette system track, a locating rack, a feed bowl stand perpendicular to the locating rack, and an output cassette feed bowl vertically arranged on the feed bowl stand, wherein the output cassette feed bowl is provided with a plurality of output trenches. The driving unit drives COB bar feed in the input trenches to move linearly so that the COB bar feed is delivered to the testing feed track from the input trenches, and the testing feed track drives COB bar feed in single layer to move linearly so that the COB bar feed is delivered to the output trenches.