Abstract: With the development of industry processes in large scale and complex, and the increasing requirements of control performance, the optimal control of distributed parameter systems are becoming more and more important. This paper studies the optimal control of distributed parameter systems by means of the approximation theory of orthogonal functions. Based on the properties of Chebyshev wavelets and its integrated operational matrices, the optimal control problem of distributed parameter systems is convened into the one of lumped parameter systems. And then, the optimal approximate control strategies for distributed parameter systems are obtained. Simulation results show the effectiveness of the proposed method.