A lens structure for mobile phone flashlight is provided, to improve luminance of edge area and overall luminance. The lens structure includes a lens body. The lens body includes an incident surface and a light-emitting surface, and the incident surface is a Fresnel lens. Edge area of the light-emitting surface is partially disposed symmetrically with at least a pair of second surfaces, and remaining area forms a first surface. The edges of the second surfaces tilt towards direction of the incident surface so that the first surface forms an angle with the second surfaces. As such, the lens structure is able to refract light to project in near rectangular area onto a target object when taking picture.