A class-D power amplifier, which prevents excessive response phenomenon from occurring when returning to a steady state from an abnormal state and an amplification method of the class-D power amplifier are provided. The class-D power amplifier prevents an integral control circuit or a proportional integral control circuit from becoming saturated by using sub-negative feedback loop operations, without using a high-capacity output blocking switch in an initial state or an abnormal state. Thus, suppressing pop noise due to the excessive response phenomenon caused when the class-D power amplifier returns to the steady state from the initial state or the abnormal state and reducing power consumption.