The present disclosure provides an image sensor, a manufacturing method thereof and a display device. The image sensor includes: a substrate; a first photodiode and a second photodiode located on the substrate, the first photodiode including a first electrode, a second electrode, and a first semiconductor structure located between the first electrode and the second electrode, the second photodiode including a third electrode, a fourth electrode, and a second semiconductor structure located between the third electrode and the fourth electrode, the first electrode being connected to the third electrode, the second electrode being connected to the fourth electrode; a switching thin film transistor, a source or a drain of the switching thin film transistor being connected to the second electrode or the first electrode; a capacitor connected in parallel with the first photodiode and the second photodiode for storing electrical signals when the image sensor receives light.