The utility model relates to a nuclear power station emergent diesel generating set exhausting auxiliary system comprising a diesel engine, an exhausting pipeline, an exhausting silencer, a condensate water discharging port, a water discharging pipe and a valve. An exhaust port of the diesel engine is connected with an inlet of the exhausting silencer via an exhausting pipeline; an outlet of the exhausting silencer is communicated with the atmosphere; the bottom of the exhausting pipeline is provided with the condensate water discharging port; and the valve is in a connection with the condensate water discharging port via the water discharging pipe. The nuclear power station emergent diesel generating set exhausting auxiliary system is characterized in that the water discharging pipe is further provided with a water accumulation tank; an inlet and an outlet of the water accumulation tank are respectively connected with the condensate water discharging port and the valve; and the water accumulation tank is equipped with a liquidometer. Condensate water storage amount can be increased with the water accumulation tank; liquid level of the condensate water can be monitored via the liquidometer, so condensate water can be timely discharged; and the nuclear power station emergent diesel generating set exhausting auxiliary system is simply structured with low cost, reliable operation and convenient maintenance.