A hybrid algorithm based on the phase mixture algorithm (PMA) and profile-smoothing algorithm is used for laser beam shaping, reducing mean square error and nonuniformity of output beam at the same time. Using the phase-modulation characteristics of liquid-crystal spatial light modulator (LCSLM), an experimental optical system is built up. The input Gaussian laser beam is shaped to flat top circular beam and rectangle beam respectively. The top beam nonuniformity and mean square error of the output beams received by CCD are less than 5%, and the energy concentration is higher than 90%. This mehod is proved to be a real-time, controllable and efficient laser beam shaping method.