We present a flat-top laser beam generation scheme using coherent beam combining of hexagonally arranged Gaussian lasers.To produce a beam with a flat-top profile,we optimize the amplitude and phase of each unit laser using the least-square method.Simulation results show that with 13 unit lasers,a beam with the flatness of less than 1%in the optimizing region can be achieved.The main lobe contains over 95% of the total power.The scheme requires no external beam shaping element and has the potential to be designed for high-power applications. We present a flat-top laser beam generation scheme using coherent beam combining of hexagonally arranged Gaussian lasers. To produce a beam with a flat-top profile, we optimize the amplitude and phase of each unit laser using the least-square method. Simulation results show that with 13 flat lasers, a beam with the flatness of less than 1% in the optimization region can be achieved. The main lobe contains more than 95% of the total power.The scheme requires no external beam shaping element and has the potential to be designed for high-power applications.