A redundant power supply control circuit including a power isolating circuit and a soft start circuit is provided. The power isolating circuit is configured to isolate a first power provided by a first power device from a second power provided by a second power device. When the first power is provided to the redundant power supply control circuit, the power isolating circuit outputs the first power as a main power, and otherwise, the power isolating circuit outputs the second power to a load. The soft start circuit is coupled to the power isolating circuit to receive the main power. The soft start circuit is enabled after the soft start circuit receives the main power, such that the soft start circuit outputs the main power to the load.