This standard specifies a standardized method for the wet disintegration of chemical pulp under laboratory conditions. Its primary objective is to fully and uniformly disperse the pulp in water through mechanical means without damaging the fibers, thereby preparing representative samples for the accurate determination of the physical properties of the pulp, such as strength and drainage performance. The key specialized instrument for the experiment is the standard disintegrator, whose specific structure, dimensions, and rotational speed must strictly comply with regulations to ensure comparability of results across different laboratories. The entire process also provides clear requirements for operational details such as water quality, pulp soaking conditions, and disintegration revolutions. It is applicable to various types of chemical pulps and recycled pulps but is not suitable for mechanical pulps.