A light detection element, including a first light detection unit, a second light detection unit, and a driving transistor, is provided. The first light detection unit includes a first transistor and a first light sensing unit. The first transistor and the first light sensing unit are electrically connected. The second light detection unit and the first light detection unit are electrically connected. The second light detection unit includes a second light sensing unit and a second transistor. The second light sensing unit and the second transistor are electrically connected. The driving transistor has a gate terminal. The gate terminal is electrically connected to the first light sensing unit and the second light sensing unit. In a time interval, the first transistor is not turned on and the second transistor is turned on.