本文用变结构方法设计柔性机械臂的模型参考自适应控制律．首先用最优状态反馈方法构造了参考模型，然后定义了末端位置误差，构造了滑模曲线，接着用变结构方法推导了自适应控制律，最后针对一具体柔性臂作了仿真研究，验证了理论的正确性并给出了一些有意义的结论． In this paper, a variable structure method is used to design the model reference adaptive control law of a flexible manipulator. Firstly, the reference model is constructed by the optimal state feedback method. Then the end position error is defined, the sliding mode curve is constructed, then the adaptive control law is deduced by the variable structure method. Finally, a simulation study is conducted on a specific flexible arm. The correctness of the theory and gives some meaningful conclusions.