Multi-source transmission system and method for instant communication file

The invention provides an instant communication file multi-source transmission system, comprising a sender instant communication terminal and a receiver instant communication terminal which are connected and exchange data through a network. The receiver instant communication terminal comprises a control module which controls file transmission, a file receiver module which is connected and exchanges data with the sender instant communication terminal, and a P2SP module which is respectively connected and exchanges data with the file sources; wherein the P2SP module of the receiver instant communication terminal finds a file carbon copy according to the file information sent by the sender instant communication terminal and receives the file from the file source in which the file carbon copyexists through multi-source transmission mode according to the control of the control module; or the file receiver module receives the file from the sender instant communication terminal according tothe control of the control module. The instant communication file multi-source transmission system finds the file carbon copy with the help of an existing P2SP system and receives the file which has a carbon copy through multi-source transmission mode, thus improving file transmission efficiency, increasing bandwidth utilization ratio and speeding up data transmission.