A power discharge control system for eliminating residual voltage of electronic components in an electronic device, is proposed, which includes a control IC for outputting first electrical signals of a first level and a second level respectively corresponding to power on and power off of the electronic device; a power supply for receiving the first electrical signal, and providing or terminating operation power to the electronic component accordingly, and delaying outputting of a second electrical signal equivalent to the first electrical signal level; a logic judgment module connected to the control IC and the power supply for receiving the first and the second electrical signals for executing logic operation process, when at least one of the first and the second electrical signals is at the first level, a third electrical signal of a third level is outputted, when both the first and the second electrical signals are at the second level, a third electrical signal of a fourth level is outputted; and at least a discharge module for receiving the third electrical signal, when the third electrical signal is at the third level, the discharge process is skipped, when the third electrical signal is at the fourth level, the discharge process is executed.