A display device, a driving control device of the display device, and a driving control method are disclosed. In one aspect, the display device comprises a display unit consisting of a plurality of pixels including a light emitting element emitting light according to a driving current corresponding to a data signal; a scan driver transmitting a scan signal through a plurality of scan lines; a data driver transmitting a data signal through a plurality of data lines; a power supply unit supplying a driving voltage to drive a plurality of pixels through a power source wire; and a driving controller connected to the power source wire, obtaining an actual output voltage value of the driving voltage output from the power source voltage supply unit, and compensating a deviation of the driving voltage in a process step by using the actual output voltage value.