This standard serves as the foundational part of the "Plastics—Acquisition and Presentation of Comparable Multipoint Data" series. It specifies the standardized methods for the entire process of obtaining, processing, and presenting mechanical property data for plastic materials. Its core purpose is to ensure the scientific comparability of plastic mechanical property test data from different sources, thereby supporting material selection, design, and engineering applications. It systematically covers testing requirements for various key mechanical properties, such as stress-strain, tensile, compression, and bending. The core testing instrument for implementing this standard is the universal material testing machine, which is used to accurately obtain performance indicators such as tensile strength, flexural strength, and elastic modulus.