GB/T 3903.8-2005 is the standard for testing the performance of the inner sole of footwear. Focusing on the peel strength test between the inner and bottom layers, it specifies the test methods applicable to the inner soles of various types of shoes. The standard clarifies the test principle and introduces the required equipment, such as the Peel strength tester. The sample preparation process is specified in detail, covering requirements such as size cutting, and also specifies the test steps, calculation and representation of results. The standard provides a unified method for evaluating the strength of the combination between the inner and bottom layers of footwear, helping to protect the mass of footwear products and safeguard the wearing experience and rights of consumers.