Unknown circuit plotting circuit and unknown circuit plotting board

The utility model relates to the field of electronic testing, and more specifically relates to an unknown circuit plotting circuit and an unknown circuit plotting board. As for the unknown circuit plotting circuit, a first circuit and a second circuit are disposed in parallel, the first circuit and the second circuit are connected in series with a power supply and a power supply switch, the second circuit comprises a first interface, a second interface, an LED lamp and a ground end, the first circuit comprises an on-off indication lamp, and when two ends of a circuit under test are respectively connected with a first interface and a second interface, whether the two ends of the circuit under test are connected or not can be determined according to that the LED lamp can glow normally or the LED lamp cannot glow but the on-off indication lamp L2 can glow. Therefore, the on-off of the circuit under test can be known through the on-off of the LED lamp and the on-off indication lamp when no measuring instrument such as a multimeter or the like is used. The measuring efficiency is improved, and the shortcomings in the prior art are solved.