The present invention provides implementation and communication methods, an apparatus and a system of a virtual subscriber identity module. The implementation method includes: receiving a VSIM application request sent by a terminal, where the VSIM application request carries an identifier of a VSIM desired by the terminal; obtaining corresponding VSIM installation information according to the identifier of the desired VSIM; and sending the VSIM installation information to the terminal, so that the terminal installs the VSIM according to the VSIM installation information. The embodiments of the present invention effectively solve a problem where an existing mobile operator network does not support the VSIM, and provide an effective and convenient operation scheme for an existing domestic or international roaming service.