This standard specifies the method for determining the particle size distribution of solid particles in coal water slurry, applicable to samples with a concentration not exceeding 60%. The core operation involves wet sieving, which combines the use of standard test sieves with specified aperture sizes and water flow rinsing to separate solid particles in the coal water slurry according to their particle sizes. The main steps of the method include sieving a representative sample using a standard sieve with an aperture of 75 micrometers, then collecting, drying, and weighing the material retained on the sieve. Finally, the mass percentage of particles larger than this aperture (referred to as the "oversize content") is calculated to characterize the particle size distribution of the coal water slurry. The primary equipment used in this method is the standard test sieve, with auxiliary equipment including an oven and a balance with a precision of 0.1 g.