Abstract: For falling motion control of humanoid robot,an approximate solution of optimal control function is obtained with classic parametric optimization methods.Based on parametric control and enhancing technique,the piece-wise constant value is used to approach the optimal solution.Then,the optimal control problem can be transformed into the parameter optimization problems.Moreover,an optimal control algorithm of falling motion for humanoid robot is proposed based on this method,and comparison with GA(genetic algorithm) is proposed.Finally,this algorithm is validated by simulation.