The invention discloses an esterification modification method for wood 
fiber biomasses, comprising the following steps of: firstly, pretreating wood 
fiber biomasses, i.e. 
drying and smashing; carrying out pre-ball milling; adding esterification 
reagent, and continuously carrying out ball milling to carry out an esterification modification reaction; and washing and 
drying products after the reaction to obtain the esterified modified products of the wood 
fiber biomasses. According to the method, various wood fiber biomasses are taken as raw materials, wide in source, low in cost, and high in 
resource utilization rate, and the conventional mode of the single 
modified cellulose can be changed; and the wood fiber biomasses are esterified in the process of ball milling, the 
esterification reaction can be carried out within a dissolved homogeneous 
system or a heterogeneous 
system in which the 
solvent is dispersion medium, and the esterification modification method is simple in modifying technology, environment-friendly, and free from the generation of 'the three wastes', and does not need recover the 
solvent. The 
infrared and weighing method result shows that the product is good in esterification effect, very good in practical applicability, and better in economic prospect.