Is the patent permanent? Under what circumstances will it fail?

It's not permanent. It has a protection period. In China, the term of invention patent right is 20 years, and the term of utility model patent right and design patent right is 10 years, both of which are counted from the date of application. PS: 1, the patent needs to pay an annual fee, otherwise the patent right will be terminated early; 2. Different countries have different patent protection periods.