Tik Tok platform implements the principle of "one case, one certificate" for all jewelry categories sold through it, and the appraisal institution designated by Tik Tok platform conducts appraisal, not the appraisal institution selected by the merchants themselves. This is helpful to ensure the fairness and consistency of appraisal, and the design of quality inspection certificate system on Tik Tok platform is helpful to ensure the quality of goods and the rights and interests of buyers.