Method, apparatus and system for transmitting files in instant messaging tool

The invention discloses one method, device and its system on instant communication tool files, which comprises the following steps: send customer end gets file transmission optimization selection message by use of designed transmission type to send files to receive customer end; the transmission type is of servo transfer type; if the designed transmission file is of point to point type, then send customer end adopts point to point send file under receive part connection establishing; if not, then adopting servo transfer type.