A pixel circuit, an active sensing array, a sensing device, and a driving method thereof are provided. The pixel circuit includes a sensing transistor, a reset transistor, and a storage capacitor. The sensing transistor is electrically connected to a sensing element and a data line. The reset transistor is electrically connected to a first scan line and the sensing transistor. The storage capacitor is electrically connected to the sensing transistor and a second scan line. During a compensation period, the reset transistor is turned on in response to a first scanning pulse from the first scan line, so that the sensing transistor is connected into a diode configuration, and the storage capacitor charges and discharges to a threshold voltage of the sensing transistor through the sensing transistor having the diode configuration in response to switching of a level of the data line.