A passive pulse cooling method for nuclear power plant, executed when a total loss of feedwater or a total loss of feedwater due to power loss superposition of the whole plant occurs, the method comprising the following steps: a steam generator isolation step: closing atmospheric relief valves (130, 230, 330) of each steam generator (10, 20, 30); a steam generator function separation step: selecting an operating mode according to requirements of emergency response strategy, and dividing all steam generators into two parts: power-operated steam generator and cooling steam generator according to the operating mode; a cooling steam generator pressure relief step: lowering pressure setpoints of the atmospheric relief valve of the cooling steam generator and waiting for the atmospheric relief valve of the cooling steam generator to open; a feedwater pipeline opening step: deisolating the feedwater pipeline of the cooling steam generator; characterized in that: the steam generator isolation step further comprises: isolating steam pipelines and feedwater pipelines between each steam generator (10, 20, 30) and a deaerator of the secondary circuit; the steam pipelines comprise: a steam header; a steam vent branch pipe (110, 210, 310) connecting each steam generator (10, 20, 30) with the steam header; a steam supply branch pipe of the deaerator connecting the steam header and the deaerator; and a steam booster pipeline connected with the steam header and the deaerator and provided with a pressurizer valve and an air-operated isolation valve (440, 450); before the feedwater pipeline opening step, the method further comprises: a deaerator first stage pressurization step: opening an air-operated isolation valve (440, 450) on the steam booster pipeline so as to pressurize the deaerator with the residual high-pressure steam in the steam pipeline; after the feedwater pipeline opening step, the method further comprises: a deaerator second-stage pressurization step: deisolating the steam vent branch pipe connected to the power-operated steam generator to maintain a pressure of the steam line of the conventional island and continuously pressurize the deaerator. a steam generator isolation step: closing atmospheric relief valves (130, 230, 330) of each steam generator (10, 20, 30); a steam generator function separation step: selecting an operating mode according to requirements of emergency response strategy, and dividing all steam generators into two parts: power-operated steam generator and cooling steam generator according to the operating mode; a cooling steam generator pressure relief step: lowering pressure setpoints of the atmospheric relief valve of the cooling steam generator and waiting for the atmospheric relief valve of the cooling steam generator to open; a feedwater pipeline opening step: deisolating the feedwater pipeline of the cooling steam generator; characterized in that: the steam generator isolation step further comprises: isolating steam pipelines and feedwater pipelines between each steam generator (10, 20, 30) and a deaerator of the secondary circuit; the steam pipelines comprise: a steam header; a steam vent branch pipe (110, 210, 310) connecting each steam generator (10, 20, 30) with the steam header; a steam supply branch pipe of the deaerator connecting the steam header and the deaerator; and a steam booster pipeline connected with the steam header and the deaerator and provided with a pressurizer valve and an air-operated isolation valve (440, 450); before the feedwater pipeline opening step, the method further comprises: a deaerator first stage pressurization step: opening an air-operated isolation valve (440, 450) on the steam booster pipeline so as to pressurize the deaerator with the residual high-pressure steam in the steam pipeline; after the feedwater pipeline opening step, the method further comprises: a deaerator second-stage pressurization step: deisolating the steam vent branch pipe connected to the power-operated steam generator to maintain a pressure of the steam line of the conventional island and continuously pressurize the deaerator. the steam generator isolation step further comprises: isolating steam pipelines and feedwater pipelines between each steam generator (10, 20, 30) and a deaerator of the secondary circuit; the steam pipelines comprise: a steam header; a steam vent branch pipe (110, 210, 310) connecting each steam generator (10, 20, 30) with the steam header; a steam supply branch pipe of the deaerator connecting the steam header and the deaerator; and a steam booster pipeline connected with the steam header and the deaerator and provided with a pressurizer valve and an air-operated isolation valve (440, 450); before the feedwater pipeline opening step, the method further comprises: a deaerator first stage pressurization step: opening an air-operated isolation valve (440, 450) on the steam booster pipeline so as to pressurize the deaerator with the residual high-pressure steam in the steam pipeline; after the feedwater pipeline opening step, the method further comprises: a deaerator second-stage pressurization step: deisolating the steam vent branch pipe connected to the power-operated steam generator to maintain a pressure of the steam line of the conventional island and continuously pressurize the deaerator.