A valve, comprising: a valve body configured to be mounted on a box body of a battery, the valve body being provided with a pressure relief port and a medium injection port configured to be connected to a fire-fighting device; a closing member connected to the valve body and closing the pressure relief port and the medium injection port, the closing member being configured to open the pressure relief port and the medium injection port when a pressure or a temperature inside the box body reaches a threshold, so as to relieve the pressure inside the box body and allow the fire-fighting device to inject a fire-fighting medium into the box body through the medium injection port; wherein the valve body comprises a body and a mounting member mounted on the body, the pressure relief port being provided on the body, and the closing member being connected to the body, and the medium injection port being provided on the mounting member; wherein the pressure relief port comprises a plurality of inlets distributed circumferentially at intervals and a plurality of outlets distributed circumferentially at intervals, and the plurality of outlets are located at peripheries of the plurality of inlets; the inlet is configured to be connected with the medium injection port when the closing member opens the pressure relief port and the medium injection port, and the outlet is configured for exhausting gas in the box body when the fire-fighting medium enters the box body through the medium injection port and the inlet in sequence; and the mounting member is provided with an exhaust port independent of the medium injection port, when the closing member opens the pressure relief port and the medium injection port, the gas can be exhausted out of the box body through the outlet and the exhaust port in sequence. a valve body configured to be mounted on a box body of a battery, the valve body being provided with a pressure relief port and a medium injection port configured to be connected to a fire-fighting device; a closing member connected to the valve body and closing the pressure relief port and the medium injection port, the closing member being configured to open the pressure relief port and the medium injection port when a pressure or a temperature inside the box body reaches a threshold, so as to relieve the pressure inside the box body and allow the fire-fighting device to inject a fire-fighting medium into the box body through the medium injection port; wherein the valve body comprises a body and a mounting member mounted on the body, the pressure relief port being provided on the body, and the closing member being connected to the body, and the medium injection port being provided on the mounting member; wherein the pressure relief port comprises a plurality of inlets distributed circumferentially at intervals and a plurality of outlets distributed circumferentially at intervals, and the plurality of outlets are located at peripheries of the plurality of inlets; the inlet is configured to be connected with the medium injection port when the closing member opens the pressure relief port and the medium injection port, and the outlet is configured for exhausting gas in the box body when the fire-fighting medium enters the box body through the medium injection port and the inlet in sequence; and the mounting member is provided with an exhaust port independent of the medium injection port, when the closing member opens the pressure relief port and the medium injection port, the gas can be exhausted out of the box body through the outlet and the exhaust port in sequence.