This is a specialized test method for evaluating the shrinkage properties of heat-shrinkable films. It clearly specifies how to determine three key indicators: hot shrinkage strength, cold shrinkage strength, and shrinkage rate. Among these, the testing of hot shrinkage strength and cold shrinkage strength requires the use of a professional film thermal shrinkage performance tester (also known as a thermal shrinkage force tester). This instrument can precisely control the heating and cooling processes while measuring and recording in real time the maximum shrinkage force generated by the film when heated (hot shrinkage force) and the maximum shrinkage force that occurs during the subsequent cooling process (cold shrinkage force). This standard is not only applicable to heat-shrinkable films made from materials such as polyethylene but also serves as a reference for evaluating the performance of heat-shrinkable films made from other types of materials.