An active surge protection structure is provided between a power line and a core circuit, comprising a surge-to-digital converter and a clamp circuit. The surge-to-digital converter comprises a plurality of surge detection circuit. Each surge detection circuit detects a surge event occurring on the power line and generates a digital signal. The clamp circuit is disposed adjacent to the core circuit and electrically connected with the surge-to-digital converter and the power line where the core circuit is connected for dissipating surge energy. The clamp circuit receives and is driven by the digital signals from the surge-to-digital converter such that its protection flexibility can be achieved according to the digital signals. By employing the present invention, it is extraordinarily advantageous of improving system stability and achieving comprehensive surge protection with configuration of driving capability dependent on surge levels.