An image sensor and a manufacturing method thereof, and an electronic device, which is capable of reducing the cost of the image sensor. The image sensor includes: a pixel array module disposed on a first wafer; a signal processing module disposed on a second wafer; an electrical connection module connecting the pixel array module and the signal processing module; wherein the pixel array module is configured to receive an optical signal and convert the optical signal into an electrical signal, and the signal processing module is configured to process the electrical signal.