The invention discloses an ultrasonic wave-based 
coal dust concentration dynamic detection 
system and 
coal dust concentration 
dynamic monitoring method of mine. Sixteen ultrasonic sensors are fixed on the inner wall of an inner ring in a uniform angle manner, and every 
ultrasonic sensor simultaneously has ultrasonic wave emitting and receiving functions; all 
signal wires are commonly connected to a multi-
core plug on an outer ring, the multi-
core plug is connected with a programmed multipath 
toggle switch through a shielded multi-core cable, the programmed multipath 
toggle switch is respectively connected with a 
voltage pulse generator and an ultrasonic 
data acquisition device through wires, the 
voltage pulse generator is connected with the ultrasonic 
data acquisition device through a wire, and the ultrasonic 
data acquisition device is connected with a 
data processing center through a wire. An existing single-emitting and single-receiving detection mode is improved to a cycle single-emitting multi-receiving CT detection mode, and an ultrasonic 
wave speed CT image and an absorption coefficient CT image are adopted to reflect the 
coal dust concentration distribution, so the detection accuracy is improved.