GB/T 3671.2-1996 specifies the method for determining the solubility of water-soluble dyestuff in cold water. The standard specifies the instruments and reagents required for the experiment, elaborates the operation process in detail, and determines its solubility by observing the dissolving status of water-soluble dyestuff in cold water under specific conditions. This standard is of great significance for water-soluble dyestuff manufacturers to control the mass of products and the rational selection of dyestuff in the printing and dyeing industry. It provides standardized testing methods for related industries and helps to improve product performance and application effects.