Hire a patent lawyer or patent agent to read the plaintiff’s patent documents to understand the case; cooperate with the patent agent to collect information, prepare documents, and submit a request for patent invalidation to the Patent Office within the 15-day defense period; on the one hand, Provide evidence of patent invalidity and request the court to suspend the litigation in accordance with the law; on the other hand, raise defenses and counterclaims against the requests and evidence in the original complaint. Legal basis: Article 872 of the "People's Republic of China and Civil Code" If the licensor fails to license the technology as agreed, he shall return part or all of the royalties and shall bear liability for breach of contract; if the licensor fails to license the technology as agreed, he shall be liable for breach of contract; If the party violates the agreement and licenses a third party to exploit the patent or use the technical secret without authorization, the party shall cease the breach of contract and bear liability for breach of contract; if the party violates the agreed confidentiality obligation, the party shall bear liability for breach of contract. If the transferor bears liability for breach of contract, the provisions of the preceding paragraph shall apply.