How to apply for a patent for free on the patent network?

The principle of the patent system is to exchange publicity for protection, that is, all patents (except confidential applications involving national defense and national security and national defense patents) can be publicly obtained, which is also a universal rule of the patent system in all countries of the world.

Specifically, in China, you can log on to the website of China National Intellectual Property Administration, www.sipo.gov.cn to download patents: click "Patent Search Query Item" under the column of "Service", click "Patent Search Analysis" after entering, and then click "Patent Search". You can search patents in many ways, such as by inventor, patentee and invention name. You can click "View File Details" for the searched patents, and you can query them after entering.