Table establishing and lookup method applied to network processor

The invention provides a table establishing and lookup method applied to a network processor. According to the method, different types of hash tables are established and adopted, and the tables are unrelated and subjected to independent two-stage lookup. The method comprises the following steps: establishing different types of hash tables according to the size of the entry of the tables to be established; allocating different memory spaces to each table; assigning the size of the tables as well as first addresses; obtaining a search key, the type of a lookup table, and the first address of the table according to information extracted from a message during looking up; performing twice hash conversion on the key at the same time, wherein in the primary conversion process, the key is converted into an offset address to determine to determine an index value of the key in an index table, and in the secondary conversion process, the key is converted into a label to distinguish conflict items; reading content from a result table according to the index value to realize matching, so as to obtain a searched result. The method effectively reduces the access number of a memory, and further improves the look-up speed of the network processor and the resource utilization rate of the memory.