In order to solve the problem of diversification of satellite mass data transmission, this paper proposes a data stream search method based on arbitrary length frame header. Firstly, the overall design process of the satellite ground baseband processing system is described. Then target the traditional search features,and the traditional data frame header search method is introduced;Finally, an implementation method based on the data flow of arbitrary length frame headers is given, and the method is introduced in detail. The results show that compared with the traditional search mechanism, the proposed search method has the advantages of high speed, high accuracy and wide range of use.