The invention discloses a content providing method and system for a large local area network based on two-layer link layer equipment. The method comprises the following steps of discovering the rest of two-layer link layer equipment based on the two-layer link layer equipment and taking the rest of the discovered two-layer link layer equipment as cache nodes of the two-layer link layer equipment; sending a data request to the cache nodes discovered by the two-layer link layer equipment based on one two-layer link layer equipment through a multicast or unicast way; and when the two-layer link layer equipment receives a data request frame of a host, checking local data storage, if data exists, sending the data to the host in a form of data frames, otherwise checking a data cache mapping table of the two-layer link layer equipment, finding the cache node stored with the data, if the cache node and the host are arranged in the same Ethernet segment, redirecting the host to the cache node, and providing data services for the host through the cache node.