A design scheme for an aspherical lens including two step processes is proposed and demonstrated to direct appropriate flux to the expected target illumination. The first-step design is based on a point source and the surface geometry is determined. The flux deviation between the design and target illumination becomes the factor in the optimization process, and the angular flux compensation is done to adjust the light pattern. Finally, the experimental result shows that high similarity between the target and the measurement is observed and full width at half maximum angle error is within 3%, which are both better than those in the aspherical lens design based a point source and a real light-emitting diode without optimization by flux compensation.