GB/T 21649.1-2024 "Particle size analysis — Image analysis methods — Part 1: Static image analysis methods" is applicable to the determination of particle size, shape, and particle size distribution through static image analysis, covering particle samples in states such as dry powders and suspensions. It specifies methods for image acquisition, preprocessing, particle recognition, and parameter measurement, clarifies technical requirements such as magnification selection and depth of field control, and details the calculation methods for characteristic parameters such as equivalent particle size and aspect ratio. It establishes unified specifications for instrument calibration, sample preparation, and result presentation, and can be used for particle size analysis of particle systems such as powders, minerals, and chemical products, ensuring the repeatability and comparability of test results.