Abstract: The micro gas chromatograph for natural gas energy metering has long been monopolized by foreign companies, creating disadvantages for China in international natural gas trade. Developing domestic alternatives is therefore of great significance. This study developed several key components for natural gas energy metering, including a micro chromatographic injection system, micro thermal conductivity detector (μ-TCD), and an online chromatographic workstation for energy value calculation. The research team has led the development of a highly reliable micro on-line gas chromatograph for natural gas energy metering with independent intellectual property rights in China. The experimental prototype has been successfully applied at natural gas flow metering stations and hydrogen production sites, analyzing 11 components in natural gas such as N₂, CO₂, and C₁–C₆ with an analysis cycle of 2.5 minutes. The detection limit for hexane is 80 μmol/mol, the resolution (R) between n-butane and isobutane is 2.0, the repeatability for n-butane quantification is 0.30%, and the 4-hour instrument stability test shows a deviation of 0.07%. The prototype has passed long-term stability testing of 6020 operating hours, meeting the requirements for natural gas energy metering. This domestically developed micro gas chromatograph represents a significant step toward replacing foreign models, providing crucial measurement technology support for national energy security and the achievement of China's "dual carbon" strategic goals.