Process for producing hydroxyethyl cellulose with high degree of substitution

The invention discloses a process for producing hydroxyethyl cellulose with high degree of substitution, and relates to the field of fine chemicals. The process adopts a multi-step method, i.e., ethylene oxide is added for multiple times in accordance with the requirements of the degree of substitution, the concentration of the ethylene oxide in a system is stabilized in a certain range, and the secondary effect speed is controlled in a lower state, which is favorable for the stable operation of positive reaction; the degree of substitution can reach 2.0-2.6, the degree of uniformity of polymer substitution can be greatly improved simultaneously, the stability of quality of products is improved, the mildew resistant performance of the products can be increased by 30%, and the shelf life of the produced latex paint is prolonged for three months; and the entire reaction process provided by the invention is controlled by a computer DCS (Data Communication System) program, the labor intensity is reduced, 12 persons can be eliminated for the same scale of production device, and the labor efficiency and the production safety are improved.