The invention discloses an index structure based on a dictionary tree, a data query optimization method and a main memory manager, and belongs to the field of data storage. The index structure is composed of containers, wherein the containers store T nodes and S nodes; complete keys are divided into partial keys; the T nodes store the front m / 2 bits of the partial keys, and the S nodes store the rear m / 2 bits of the partial keys; and the partial keys passing through a certain node path from the root node of the dictionary tree are connected to form the complete keys. And the index structure ismore compact, so that the main memory space utilization rate is improved. The T node is directly skipped to a subsequent brother node by using a skipping relay, so that the comparison frequency is reduced, and the search performance is improved; a T node skip list is used for skipping a T node to an S node, a container skip list is used for skipping the S node to the T node, and the S node directly skips to the nearest target, so that a large number of unnecessary entries are skipped, and the searching performance is improved; and the index structure and the main memory address are completelydecoupled by a pointer P which is analyzed by the main memory manager and contains each hierarchical structure ID.