A switching device includes: a first switching circuit, having a control node coupled to a first control signal, and arranged to selectively couple a signal node to a first amplifying circuit according to the first control signal; and a first control circuit, having a first control node and a second control node coupled to the control node of the first switching circuit and the signal node, respectively, wherein when the first switching circuit is controlled to electrically disconnect the signal node from the first amplifying circuit and a voltage level of the signal node reaches a first predetermined voltage level, the first control circuit is arranged to make the control node of the first switching circuit electrically connected to the signal node.