Can the patent be extended indefinitely?

Legal analysis: a patent cannot be extended indefinitely, nor can it be extended after the expiration of the patent term. Patents are the scope of protection for a fixed period of time, and they become known technologies after expiration.

If you think the technical scheme needs to be kept secret for a long time, you can protect it with technical secrets, but there is a risk that if someone applies for a patent in advance, it will lead to their own infringement risk.

Legal basis: Article 42 of the Patent Law of People's Republic of China (PRC) has a term of 20 years, and the term of utility model patent and design patent is 10 years, counting from the date of filing.