The invention belongs to the technical field of adsorption material preparation, aims to solve the problems that conventional filtering materials cannot absorb harmful substances in 
wastewater and get agglomerated easily, and provides a 
processing technology of a walnut shell filtering material. The 
processing technology comprises the following steps: removing the impurities, disinfecting the walnut shells, washing, 
drying, 
grinding, 
polishing, 
steaming and washing to remove the 
grease, 
polishing the walnut shells in a cylinder 
polishing machine to remove the projected parts on the surface and reach a 
surface roughness of Ra0.8; 
steaming and washing the walnut shells in a 
steaming and washing 
machine for 1 to 3 hours; 
degreasing the walnut shells in a baking oven with a temperature of 85 to 90 DEG C for 20 hours until the 
water content is less than 8%; irradiating the walnut shells by UV rays with a 
wavelength of 185 nm for 20 hours to kill the 
bacteria; and finally screening and grading so as to obtain the walnut shell filtering material. The prepared walnut shell filtering material can absorb suspensions and harmful substances in 
wastewater. During the application process, the 
hardness of the provided filtering material is high, the filtering material will not get rotten or agglomerated, the 
toughness of the filtering material is high, moreover, the filtering material can be easily regenerated, thus the replacement frequency is reduced, the labor and time are saved, and the cost is low. The 
processing technology is simple, the 
water quality can be improved effectively, the 
raw material sources are wide, and the using effect is prominent. The provided novel filtering material can greatly reduce the 
water treatment cost.