The invention relates to an alarming method of a high-pressure electrostatic purifying device. The alarming method comprises the steps that firstly, the added weight of the high-pressure electrostaticpurifying device is detected, when the increased weight exceeds a set increased weight threshold and it is detected that the current of the high-pressure electrostatic purifying device is greater than a set current threshold, it is considered that pollutants accumulated on the high-pressure electrostatic purifying device are excessive, and a protecting mechanism is started; and when the increasedweight does not exceed the set increased weight threshold and it is detected that the current of the high-pressure electrostatic purifying device is greater than the set current threshold, the high-pressure electrostatic purifying device suspends working for a period of time, then working is restarted, but alarming is not directly conducted, and only when the number of work-suspending times of the high-pressure electrostatic purifying device exceeds a set stopping time threshold, the protecting mechanism is started. According to the alarming method of the high-pressure electrostatic purifyingdevice, the situation that the protecting mechanism is mistakenly started is solved through the increased weight of the high-pressure electrostatic purifying device. Through the exhaust hood applyingthe alarming method of the high-pressure electrostatic purifying device, the user experience can be improved, and the product quality is improved.