The present disclosure provides a method and system for content delivery used in a mobile terminal application. The method includes: (a) integrating, by the mobile terminal application, a software development kit (sdk) into the mobile terminal application, importing a download request into the sdk, and waiting to receive downloaded data; (b) receiving, by the sdk, the download request imported by the mobile terminal application, downloading an initial packet from a cache system or a source station based on the download request, and determining if P2P download can be started based on the initial packet, the initial packet being an initial data fragment of data to be downloaded; (c) when it is determined to start the P2P download, fragmenting, by the sdk, remaining undownloaded data to a plurality virtual files; and (d) sequentially downloading the plurality of virtual files and caching a download result until downloading of all of the virtual files is completed.