Boiler expansion monitoring method and system

The invention relates to the technical field of boiler expansion monitoring, and discloses a boiler expansion monitoring method and system, and the method comprises the steps: presetting a plurality of monitoring sub-regions, collecting expansion measurement data of the monitoring sub-regions, transmitting the expansion measurement data to a same receiving device, and drawing an expansion measurement data change curve according to the expansion measurement data; determining a first quantity value according to the expansion measurement data change curve, collecting preset support hanger activity data and correcting the first quantity value to generate a second quantity value; judging an expansion state according to the second quantity value, and sending an alarm signal if the expansion state is abnormal; the method comprises the following steps: establishing a plurality of monitoring sub-areas, receiving expansion measurement data of each monitoring sub-area, activity data of important supports and hangers, a