A capacitive pressure sensing device includes a capacitor, a capacitive pressure transducer, a resistor, a capacitance/frequency converter and a processor. The capacitive pressure transducer includes a metal sponge, a metal layer and a capacitive sensor element. The metal sponge is sandwiched between the metal layer and the capacitive sensor element. When an external force is applied to the metal layer, the metal sponge is compressed, and reduces a distance between the metal layer and the capacitive sensor element, the capacitive pressure transducer thus produces a variable capacitance value Ct. The total capacitance value at an input terminal of the capacitance/frequency converter is contributed by the capacitor and the capacitive pressure transducer. The capacitance/frequency output a control signal according to the total capacitance value to an electronic device to trigger a corresponding function.