The invention discloses a safe access method for the power VoLTE business. The method comprises the following steps: carrying out authentication of employee information of a mobile terminal user; carrying out translation of IMS voice based on the UDP, and carrying out transmission through a safe TCP connection; and carrying out communication between a safe chip and a safe access platform deployed at the boundary of an external information network. The device comprises power VoLTE safe terminals, a power VoLTE safe access server, and main station side equipment, wherein the power VoLTE safe terminals comprise an IMS mobile client and a safe access platform client; the power VoLTE safe access server comprises a safe access platform server; the main station side equipment is an IMS server; the IMS server is connected with the safe access platform server through conversion from TCP to IMS UDP; the power safe access platform server is connected with the safe access platform client; and the safe access platform client is connected with the IMS mobile client through conversion from IMS UDP to TCP. The method and device provided by the invention has the characteristics of few changes to the terminal equipment, high portability, economization and easiness in use, and high safety and flexibility of an access mode.