However, there are some limitations and disadvantages. The limitations are that: firstly, you can't apply for a patent for utility model, but you can only apply for an invention patent. This is not a big problem, because the utility model patent is too lacking in stability guarantee, so it is fine not to apply. Another limitation is that it can't be a pure intellectual activity rule, and it should be related to shape and structure.
If it's not just for that certificate, and if there is no product patent to apply at the same time, it is suggested that you don't apply for a design method patent, so you should publish a paper or change it to a product patent or a manufacturing method patent. Because, applying for a design method patent is tantamount to making your core secrets public, and you can't confirm whether others have used your design method, and you can't be protected from infringement. Why dig a hole for yourself?