The present application provides a turn-on voltage supplying circuit and method, a defect analysis method and a display device. The turn-on voltage supplying circuit includes a voltage supplying unit and a switching unit. The voltage supplying unit is configured to provide turn-on voltages, values of which being within a predetermined range, to the M stages of gate driving circuits respectively in the case that the M stages of gate driving circuits are in a normal operation state, or provide corresponding turn-on voltages to the gate driving circuits in the case that the gate driving circuits are subject to a defect analysis process. M is an integer greater than 1. When the gate driving circuits are subject to the defect analysis process, the voltage supplying unit comprises variable resistors connected between a reference turn-on voltage outputting terminal and the turn-on voltage inputting terminals of the gate driving circuits.