This standard specifies the method of dispersing pigments and extenders using an automatic flatmill. It is suitable for the dispersion performance evaluation of small samples, mainly for pigment quality control. The test process uses a high-viscosity paint-based system, which is used in combination with the evaluation method of GB/T 21867. This method is limited to high-viscosity grinding materials, and the results obtained cannot be directly compared with the Miscellaneous dispersion method. The automatic flatmill method is easy to operate and has strong repeatability. It is suitable for rapid dispersion evaluation of small samples.