1. Wear of the base: If the base of the thermos cup is worn, try to smooth the worn part gently with sandpaper or abrasive, and then apply some lubricant, such as vaseline or silicone oil, to reduce friction and wear.

2. The base is broken: If the base of the thermos cup is broken, consider taking the thermos cup to a professional repair shop or contacting the manufacturer for repair or replacement. Before maintenance, it is best to clean the thermos cup and dry the inside.

3. The base leaks: If the base of the thermos cup leaks, you can try to turn the thermos cup upside down and check whether the base is damaged or cracked. If there is any damage or crack, it can be repaired according to the above method. If it cannot be repaired, please contact the manufacturer or professional repair shop for replacement.