This document specifies the Chinese ISO standard sand particle size detection method, including principle, instrument and equipment, sample prepative, detection method and results. It is divided into two types: sieve analysis method and laser method. The sieve analysis method is suitable for particle size detection in the production process of standard sand and qualified judgment when it leaves the factory, while the laser method is a substitute method and is suitable for particle size detection in the production process of standard sand. GB/T 6003.1 and JC/T 721-2006 are cited. The terms and definitions follow these two standards. The sieve analysis method utilizes a square-hole sieve for grading. The instrument and equipment include a test sieve, a balance and a sampler.