This standard specifies the method for determining the surface coating thickness of wooden furniture components, enabling the quantitative evaluation of the uniformity and stability of coating processes through scientific means. The core principle of the test is based on ultrasonic pulse reflection technology, which leverages the reflective properties of ultrasonic waves in different media to achieve high-precision measurements without damaging the coating. The key equipment for performing this test is a specialized ultrasonic coating thickness gauge, designed specifically for non-metallic substrates such as wood. These instruments are typically equipped with high-precision probes, capable of measuring thicknesses up to thousands of micrometers with micron-level accuracy. During testing, a specialized couplant must be applied to the sample surface to ensure good contact between the probe and the coating. Multiple measurement points are taken to evaluate the overall thickness. This method is applicable to finished furniture or specialized test samples, providing an objective and non-destructive testing tool for quality control and process improvement in furniture production.