The invention provides a method of preparing chestnut shell 
brown pigment by ultra-
micronization in cooperation with pulsed 
electric field, comprising the steps of (1), cleaning, washing and 
drying chestnut shells and then primarily crushing the chestnut shells; (2), adding coarse chestnut shell 
powder into an ultra-
micronization apparatus for wall breaking to obtain chestnut shell superfine 
powder; (3), using 
ethanol solution as an extracting 
solvent to extract the chestnut shell superfine 
powder by the aid of a pulsed 
electric field treating device, filtering, and combining double extracts to obtain 
pigment extract; (4), concentrating the 
pigment extract under reduced pressure to 1 / 3 of the original size, and carrying out 
alcohol precipitation, 
solid-liquid separation, concentration and 
drying to obtain the chestnut shell 
brown pigment that is powdery. The ultra-
micronization and pulsed 
electric field treating techniques are combined, no heating is required to provide quick and complete 
dissolution of the chestnut shell 
pigment, extracting time and energy can be greatly saved, and the method has the advantages of rich material sources, low extracting temperature, high product yield is high, short 
treatment time, good operational simplicity and the like; the obtained chestnut shell 
brown pigment has 
high color intensity, good water-
solubility, stable quality, safety with no 
toxicity and is worthy of practical production and conversion and practical popularization and application.