Nitrogen filling maintenance method in boiler during shutdown standby of boiler

The invention discloses an in-boiler nitrogen filling maintenance method for boiler shutdown standby. The in-boiler nitrogen filling maintenance method comprises the steps that a nitrogen making component is connected to an inlet of a boiler drain pipe through an electric flow dividing valve; a first detection part is arranged in the boiler, and oxygen concentration data in the boiler is obtained; a second detection part is arranged at the output end of the nitrogen generation part, and nitrogen concentration data generated by the nitrogen generation part are obtained in real time; the oxygen concentration data and the nitrogen concentration data are analyzed through the control module, and actions of the nitrogen generation component and the electric flow dividing valve are controlled according to an analysis result; the oxygen content of the shutdown standby nitrogen charging maintenance boiler is detected in real time, the nitrogen concentration in the boiler is reflected, and the nitrogen making machine i