GB/T 43938.1-2024 is Part 1 of the series of standards for the mechanical property testing of carbon fiber reinforced composite thin-walled tubes. It specifies the test requirements for axial tensile properties and applies to such tubes with a wall thickness not exceeding 1 mm and a nominal outer diameter less than 50 mm. The core measurements include tensile strength and elastic modulus. The standard defines specimen preparation, environmental conditions, and loading procedures, employing end reinforcement sleeves with specialized fixtures to prevent test damage. The testing requires the use of a Class 1 precision electronic universal testing machine, an axial extensometer with a resolution no lower than 1×10⁻⁴, a wall thickness gauge with an accuracy of 0.01 mm, and an outer diameter gauge with an accuracy of 0.02 mm. This standard provides a unified technical basis for material development and quality control in fields such as aerospace.