Safety method of D2D mode B discovery, terminal and system

The present invention discloses a safety method of D2D mode B discovery. In the four processes of the discovery service of the D2D mode B, through adding a corresponding parameter, the integrity protection of the discovery response message of a passive terminal, the discovery response message of an active terminal, the inquiry request message sent to the passive terminal by the active terminal, the inquiry response message sent to the active terminal by the passive terminal, and the matched report message of the active terminal is carried out. The invention also discloses a safety system and terminal of D2D mode B discovery.