The invention discloses an emulsifier safe running cutting off monitoring device used in explosive product line. The plate is rigidity material and has sliding surface. One end of the plate is under the outlet of the emulsifier, and the other end is connected to the up end of spring. The down end is fixed. The signal collector is located on the up end that the plate connecting to the spring to collect cut off signal, and the controller process the signal and send out alarm or stop instruction. Comparing to the existing monitor device, it could continuously and reliably auto monitoring. It could decrease the errors by man judgment and effectively improves the safety of the device.