With the increasing number of flights in recent years, it has become an inevitable development trend to apply all kinds of flight surveillance equipment data for localized development to improve aviation control safety and control efficiency. As a data exchange standard for various flight surveillance equipment, ASTERIX involves many kinds of protocols. Analyzing these protocols is the key to realize the secondary development and application of surveillance equipment data. Taking CAT021 data as an example, a general analysis algorithm for ASTERIX protocol data is provided, and a set of general data analysis program implementation framework is completes according to the algorithm.