An image sensing device for sensing an image sensing pixel array through a plurality of sensing lines is provided. The image sensing device includes a first switch, a second switch, a transistor, and a current source. A first terminal of the first switch is coupled to a first sensing line among the sensing lines. A first terminal of the second switch is coupled to a second sensing line among the sensing lines. A first terminal of the transistor is coupled to a second terminal of the first switch and a second terminal of the second switch. The current source is coupled to a second terminal of the transistor.