The invention discloses a search method and device on the basis of static Cache, an index data generation method and device used for static Cache, and a method and a device used for obtaining a query
syntax tree identifier. The search method on the basis of the static Cache comprises the following steps: receiving a search request of a
client side; according to query information in the search request, generating a query
syntax tree; looking up a pre-generated high-frequency
syntax tree from the query syntax tree, and replacing parts of query information corresponding to the high-frequency syntax tree in the query information with a
unique identifier, which is pre-calculated, of the high-frequency syntax tree according to a sequence from a root node to a leaf node, wherein the
unique identifier of the high-frequency syntax tree is used for quickly recalling a search result corresponding to parts of query information from an index
database in a retrieval stage; and according to the replaced query information, retrieving the index
database, and returning the search result to the
client side. The above method can reduce performance cost generated when a
search engine carries out inverted recalling, and improves the retrieval performance of the
search engine.