Implementation and communication methods, an apparatus and a system of a virtual subscriber identity module (VSIM) are provided. 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. According to the present application, a problem where an existing mobile operator network does not support the VSIM is effectively solved, and an effective and convenient operation scheme is provided for an existing domestic or international roaming service.