To be able to apply for an invention patent, it must have the following characteristics: (1) Outstanding substantive characteristics, that is: compared with the existing technology, the invention is non-obvious to technicians in the technical field to which it belongs. If an invention can be obtained by a skilled person in the technical field to which it belongs through logical analysis, reasoning or limited experiments based on the existing technology, then the invention is obvious and does not have outstanding substantive features, so it cannot be patented; Non-obvious and outstanding substantive features can be patented. (2) Significant progress: if the invention can produce beneficial technical effects compared with the existing technology. Beneficial means: the invention has better technical effects than the existing technology, such as quality improvement, output increase, energy saving, environmental pollution prevention, etc.; the invention provides a technical solution with a different technical concept, and its technical effects can basically reach the level of existing technology; the invention represents a certain new technology development trend: although the invention has negative effects in some aspects, it has obvious positive technical effects in other aspects, etc.