The history of railway gauge can be traced back to the coal mine transportation era in the UK, where the track spacing was set at four feet eight and a half inches (1435mm), which later became the standard gauge for railway systems worldwide. In 1825, Stephenson, the inventor of the steam locomotive, adopted this gauge, and with the spread of railway technology, this standard gradually gained adoption in the United States, Germany, and other regions.

China's railway construction began in the 1880s, when foreign powers exported railway technology and products to China through loans, bringing various technical standards with them. Therefore, China's railway gauge system initially showed diverse characteristics, with British, French, Russian, and other standards coexisting. This chaotic state of gauge systems persisted for nearly a century until the late Qing Dynasty, when there was a gradual move towards unification.

During the process of unifying the gauge system, the influence of the UK was the most significant. Since most of China's earliest railways were built or assisted by the British, the British gauge was widely used in China. However, some railways also adopted standards from other countries, such as the French standard for the Lu-Han Railway and the Russian standard for the Eastern Qing Railway.

To address this issue, the Chinese government and relevant authorities began to carry out gauge system reforms. They gradually unified the national railway gauge system by formulating relevant regulations and standards. Ultimately, the standard with a British gauge of four feet eight and a half inches, Martin steel as the material, and a mainline track weight of 85 pounds was established as the standard for China's railways. This standard not only applies to railway mainlines but has also been gradually extended to other railway lines.

Since then, China's railway gauge standard has been followed to this day and continues to develop and improve. The establishment of this standard has not only improved the operational efficiency and safety of China's railways but also laid a solid foundation for the modernization of China's railway development.