In the technical solutions of a high dynamic range image synthesis method and an electronic device provided in embodiments of this application, a plurality of images with different depths of field in a current photographing scene are obtained based on an HDR photographing operation entered by a user, and each image has an exposure value. A plurality of images with a same exposure value are synthesized to generate a full depth-of-field image. Full depth-of-field images with a plurality of exposure values are synthesized by using an HDR algorithm to generate a high dynamic range image. Therefore, a high dynamic range image that is clear at each depth of field can be obtained, and a problem that a shallow depth of field leads to a blurred background and an insufficient dynamic range, and then results in overexposure or underexposure of a high dynamic range image can be resolved.