The simplex algorithm is introduced and the control inputs form mapping with Zernike polynomial coefficients because the amount of calculation if large when liquid crystal space light modulator directly compensate wavefront phase distortion.The performance metric if optimized and theexcellent Zernike polynomial if obtained which can realize precise compensation for wavefront distortion.The simplex algorithm is modified because the traditional simplex algorithm easily converges to the local minimums and the global optimization can not be achieved.The simulation results show that the modified simplex methods can force initialization to achieve the global optimization,and the analyses to the characteristics of modification provide basis for practical application.