This paper deals with the state-of-the-art development of the fixed-bed reactor and discusses the possible progress to be made in the future. As a traditional reactor，the fixed-bed can be seen quite satisfactory as far as its model theory itself is concerned. However，it is almost impossible to optimize the reactor based on the models since obvious uncertainty is involved in the model structure and model parameters. Therefore, from scientific methodology point of view , the dynamic optimization，relied on state and parameter estimation, is discussed. A possible tendency is to update fixed-bed reactors by taking advantage of some related technologies，such as inorganic membrane and catalyst design，in order to realize reaction-separation combination. Finally，this paper emphasizes the importance of combining the existing theories and principles，to make the fixed-bed reactor with tow energy consumption and high yield