The invention relates to an online 
measurement device and method for boiler pulverized 
coal particle parameters. The device comprises an optical 
signal collection unit and a 
data processing unit, wherein the optical 
signal collection unit is used for collecting an optical 
signal caused by that pulverized 
coal particles flow through a measurement area, and comprises two paths of light sources, probes and a photoelectric element, the light sources are used for emitting light to irradiate the measurement area, the two paths of probes are inserted into a boiler pulverized 
coal particle pipeline, the photoelectric element is used for receiving the optical signal of the pulverized coal particles flowing through the measurement area and converting the optical signal into an electrical signal, the 
data processing unit is connected with the optical signal collection unit, and is used for 
processing the signal collected by the optical signal collection unit, the 
data processing unit comprises a data 
collection system and an analyzing and 
processing system, the data 
collection system is used for recording and storing the signal collected by the optical signal collection unit, the data 
processing unit is used for processing the signal recorded and stored by the data 
collection system, and a processing result is stored in the data collection 
system. The online 
measurement device and method have the advantages that a structure principle is simple, the sensitivity is high, and the like.