A discharging apparatus for an electric vehicle having a motor, comprising: an AC charging interface, connected with a charging pile and configured to transmit an AC to a power grid via the charging pile, the charging pile being connected with the power grid; an instrument, provided with a panel having an external discharge button, wherein when the external discharge button is pressed, the instrument sends a message indicating an external discharging mode to inform a controller; the controller, configured to communicate with the instrument and to detect whether there is an electric vehicle gear signal, and to determine whether the electric vehicle is in P gear and whether the motor is in undriving mode when there is no electric vehicle gear signal after receiving the message, and to detect a CC signal to determine whether the charging pile is connected to the electric vehicle and whether a resistance of CC is a standard value when the electric vehicle is in P gear and the motor is in undriving mode, and to detect whether there is a PWM wave with a predetermined voltage in the controller when the CC signal is detected and the resistance of CC is a standard value, and if there is a PWM wave with a predetermined voltage in the controller, to switch to the external discharging mode; a battery manager, configured to communicate with the controller and to control an external discharging circuit in a high-voltage distribution box of the electric vehicle to be connected after the controller switches to the external discharging mode; a power battery, connected with the high-voltage distribution box; wherein the controller is configured to detect whether an electric quantity of the electric vehicle is greater than a predetermined value, and if yes, to convert a DC provided by the external discharging circuit into the AC and to output the AC to the AC charging interface so as to discharge to the power grid, when the electric vehicle is in OK gear with P gear, the instrument starts to serve, when the controller is in service, if the electric vehicle is not in P gear and/or the motor is not in undriving mode, a message indicating "forbid external discharge" is sent to the instrument, and if the CC signal is not detected and/or the resistance of CC is not the standard value, the message indicating "forbid external discharge" is sent to the instrument. an AC charging interface, connected with a charging pile and configured to transmit an AC to a power grid via the charging pile, the charging pile being connected with the power grid; an instrument, provided with a panel having an external discharge button, wherein when the external discharge button is pressed, the instrument sends a message indicating an external discharging mode to inform a controller; the controller, configured to communicate with the instrument and to detect whether there is an electric vehicle gear signal, and to determine whether the electric vehicle is in P gear and whether the motor is in undriving mode when there is no electric vehicle gear signal after receiving the message, and to detect a CC signal to determine whether the charging pile is connected to the electric vehicle and whether a resistance of CC is a standard value when the electric vehicle is in P gear and the motor is in undriving mode, and to detect whether there is a PWM wave with a predetermined voltage in the controller when the CC signal is detected and the resistance of CC is a standard value, and if there is a PWM wave with a predetermined voltage in the controller, to switch to the external discharging mode; a battery manager, configured to communicate with the controller and to control an external discharging circuit in a high-voltage distribution box of the electric vehicle to be connected after the controller switches to the external discharging mode; a power battery, connected with the high-voltage distribution box; wherein the controller is configured to detect whether an electric quantity of the electric vehicle is greater than a predetermined value, and if yes, to convert a DC provided by the external discharging circuit into the AC and to output the AC to the AC charging interface so as to discharge to the power grid, when the electric vehicle is in OK gear with P gear, the instrument starts to serve, when the controller is in service, if the electric vehicle is not in P gear and/or the motor is not in undriving mode, a message indicating "forbid external discharge" is sent to the instrument, and if the CC signal is not detected and/or the resistance of CC is not the standard value, the message indicating "forbid external discharge" is sent to the instrument.