A keyswitch assembly includes a keycap, a lifting mechanism, a shield, and a substrate. The lifting mechanism includes a keycap end coupled to the keycap and is capable of being driven by a force to move downward by a distance. The shield extends from the keycap end or the keycap and is movable along with the keycap end or the keycap. The substrate is disposed below the lifting mechanism and includes a sensing switch and a keyswitch circuit electrically connected to each other. The sensing switch has a signal channel and is configured to sense a change in sensed intensity caused by interference of the shield with the signal channel to cause the keyswitch circuit to generate at least one keyswitch signal. During movement of the shield with the keycap end or the keycap, the shield interferes with the signal channel as much as possible throughout the entire distance.