The invention relates to a preparation method of a damping material used for installing a draught fan. The preparation method comprises the following steps: 1, putting nanometer 
carbon black, silica 
sol and addition agents into waterborne 
polyurethane latex, conducting ultrasonic treatment, and obtaining composite 
emulsion for standby application; 2, conducting mixing, 
grinding and dispersing on expanded 
vermiculite, 
cristobalite, 
bentonite and 3-phenyl-2-propyl 
acrylate for 2-2.5 h, mixing the obtained materials with other residual materials, stirring the mixture evenly and sufficiently, putting the mixture into a twin-screw extruder, conducting prilling by fusing and 
extrusion at the temperature 
ranging from 180 DEG C to 190 DEG C, and obtaining modified master batches; 3, putting the modified master batches into a screw extruder for being fused, spraying the flux out through a melting-spraying die 
head spinning orifice at the temperature 
ranging from 230 DEG C to 250 DEG C, stretching the flux under the effect of high-speed hot air flow, putting the flux into a receiving device, and after the composite 
emulsion is solidified and dried completely, obtaining the finished damping material. The phenolic resin damping material wrapped by expanded 
vermiculite-
polyurethane composite 
emulsion which is obtained through preparation is low in 
mass, small in thickness and quite good in damping effect.