Method and system for controlling exhaust gas temperature of boiler

The embodiment of the invention provides a method and a system for controlling exhaust gas temperature of a boiler, and belongs to the field of electric power. The method comprises the following stepsthat the first exhaust gas temperature of exhaust gas after the exhaust gas passes through a spraying device is detected; and moreover, a total fuel trip of the boiler is triggered when the first exhaust gas temperature is detected to meet any one of the following conditions, wherein one condition is that the duration time of the first exhaust gas temperature being larger than the first thresholdvalue reaches preset first time, the other condition is that the duration time of the first exhaust gas temperature being larger than the second threshold value reaches preset second time, the firstthreshold is larger than the second threshold, and the first time is smaller than the second time. According to the technical scheme, the exhaust gas temperature obtained after the exhaust gas passesthrough the spraying device