The invention provides a monitoring method for vertical milling cutting vibration. The monitoring method comprises the steps that in the process of acceleration signal obtaining, an acceleration sensor installed on a main shaft of a vertical milling cutting machine is used for collecting acceleration signals produced in the vertical milling cutting process, the acceleration signals are shown as the formula: X=[x(1), x (2),..., x(n)], n represents the signal length, and the acceleration signals comprise the stable state signals, the transition state signals and the vibration state signals, all of which are located in different frequency bands. According to the monitoring method for vertical milling cutting vibration, the acceleration signals are utilized as reflecting signals of cutting vibration, an energy ration coefficient and a singularity spectrum entropy coefficient are calculated based on the signals to serve as a training sample of a BP neural network, and a vibration monitoring result is finally obtained. Compared with a common vibration detecting method, the sign of the cutting vibration can be found earlier, precise recognition is achieved before sharp vibration, and irretrievable harm caused by sharp vibration to workpieces and machine tool components is prevented.