The invention relates to a method for detecting positive and saturation voltage drop of a transistor chip of a discrete device. The method for detecting the positive and saturation voltage drop of a transistor of a discrete device is characterized in that a metal bearing sheet desk tray (4) under a transistor chip (1) is connected with a collector input current wire (41) of a tester, a collector feedback voltage probe (51) is tied to a scribing groove (5) on the periphery of the transistor chip (1), the collector feedback voltage probe (51) is connected with the collector feedback voltage wire of a tester, and the tester is turned on to test the transistor chip of the discrete device. According to the method provided by the invention, the input current wire and the feedback voltage wire of the collector on the back of the transistor chip are separated, so that the omnibearing Kelvin test can be realized by the transistor chip of the discrete device, and the accurate testing of the positive and saturation voltage drop of the transistor chip of the discrete device can be ensured.