The present invention discloses an IEC61850-9-2 network storm dynamic monitoring method of a merging unit device. The method is characterized by comprising a first step that a merging unit analyzes a received IEC61850-9-2 packet; and a second step that whether the packet has a storm packet is determined by using a two-point monitoring method, wherein if the packet has the storm packet, a storm identifier is set 1, and the channel quality of a packet in an output cache is set invalid. According to the method, wrong data information is effectively prevented from being output, and the running stability of the merging unit device is improved. On the basis of the IEC61850-9-2 storm packet monitoring, multi-level control is performed by using control words, the method has high openness and flexibility, the network storm monitoring function has high anti-interference while basic functions of the merging unit device are realized, the data transmission security is ensured, and the monitoring method ensures that the merging unit device can run safely.