A dual-core focusing image sensor is disclosed. The dual-core focusing image sensor includes a photosensitive cell array including a plurality of focus photosensitive units, each of which including a first half and a second half and a plurality of dual-core focusing photosensitive pixels; a filter cell array disposed above the photosensitive cell array and including a plurality of white filter cells; and a micro-lens array disposed above the filter cell array and including a plurality of first micro-lenses, each of which having an elliptical shape and a plurality of second micro-lenses. The first half is covered by one of the white filter cells and the second half is covered by a plurality of the second micro-lenses, each of the white filter cells is covered by one of the first micro-lenses. Each of the dual-core focusing photosensitive pixels is covered by one of the second micro-lenses.