Abstract: Based on the study of the OIML Certification System (OIML-CS), this paper expounds on the implementation of the OIML-CS in China. The practice shows that China as a major country in the manufacture and use of measuring instruments actively carries out and implements the OIML-CS, which is conducive to promoting the dual improvement of the measuring instruments quality and the legal metrological supervision ability, and is of great significance to the development of China's measuring instrument industry.