The present disclosure relates to a method of electrically aging a PMOS thin film transistor. The method includes applying a first voltage Vg with an amplitude of A volts to a gate of the PMOS thin film transistor; applying a second voltage Vs with an amplitude of (A−40) to (A−8) volts to a source of the PMOS thin film transistor; and applying a third voltage Vd with an amplitude of (A−80) to (A−16) volts to a drain of the PMOS thin film transistor. Application of the first voltage Vg, the second voltage Vs and the third voltage Vd is maintained for a predetermined time period, and Vd−Vs