legal analysis: the defense methods of trademark infringement defendants are as follows: 1. fair use defense; 2. The defense of prior use. Before the trademark registrant applies for trademark registration, someone has used a trademark that is the same as or similar to the registered trademark and has certain influence before the trademark registrant. The exclusive right to use a registered trademark has no right to prohibit the user from continuing to use the trademark within the original scope of use, but he may require it to attach an appropriate distinguishing mark; 3, legitimate source defense, selling goods that are not known to infringe the exclusive right to use a registered trademark, can prove that the goods are legally obtained by themselves and explain the provider, and will not be liable for compensation.

legal basis: article 47 of the trademark law of the people's Republic of China a registered trademark that has been declared invalid in accordance with the provisions of articles 44 and 45 of this law shall be announced by the trademark office, and the exclusive right to use the registered trademark shall be regarded as nonexistent from the beginning. A decision or ruling declaring a registered trademark invalid has no retrospective effect on the judgments and rulings of trademark infringement cases made and executed by the people's court before the invalidation, the conciliation statement, the decision on handling trademark infringement cases made and executed by the administrative department for industry and commerce, and the trademark transfer or use license contract that has been executed. However, the losses caused to others by the malice of the trademark registrant shall be compensated. If the trademark infringement compensation, trademark transfer fee and trademark use fee are not returned in accordance with the provisions of the preceding paragraph, which obviously violates the principle of fairness, they shall be returned in whole or in part.