GB/T 18945-2003 provides a method for estimating the flow rate of polymer porous resilience materials under constant pressure drop. The standard defines the applicable material range, elaborates on the selection and preparation of samples, specifies the equipment required for experiments, and specifies the operation process of measuring the flow rate under specific pressure drop conditions, including pressure setting, data recording, etc., and also clarifies the calculation and representation method of the results. The standard provides a unified basis for the performance evaluation of polymer porous resilience materials in relevant application scenarios, helps enterprises control the mass of products, and promotes the development and standardization process of industry technology.