Grade I: Earpieces are dark brown with a bright feeling, and the back is gray; No boxing ears, flowing ears, lost ears, insect ears and moldy ears are allowed; The petals are intact and cannot pass through a sieve with a diameter of 2cm; The water content cannot exceed14%; The dry-wet ratio is above 1: 15; The thickness of lifting lug is above 1mm; Impurities should not exceed 0.3%.

Grade 2: the ear pieces are dark brown and the back is dark gray; No boxing ears, flowing ears, falling ears, moth-eaten ears and moldy ears are allowed; The petals are intact and cannot pass through a sieve with a diameter of 2cm; The water content shall not exceed14%; The dry-wet ratio is above 1: 14; The thickness of the tab should be above 0.7mm, and the impurity should not exceed 0.5%.

Grade three: the luster of ear parts is mostly dark brown or light brown; The boxing ear shall not exceed1%; Flow ear does not exceed 0.5%; Ear loss, insect-eaten ear and moldy ear are not allowed; Each flower is too small or fragmented to pass through a sieve with a diameter of 0.4cm; The water content shall not exceed14%; The dry-wet ratio is above 1: 12; Impurities shall not exceed 1%.