Take the required amount of hot water, put it into a container and heat it to above 85°C, and gradually add this product under slow stirring. The cellulose floats on the water at first, but is gradually dispersed to form a uniform slurry. Cool the solution. Or heat 1/3 or 2/3 of the hot water to above 85—, add cellulose to obtain a hot water slurry, then add the remaining amount of cold water, keep stirring, and cool the obtained mixture.