How can I prove that I am the first method without applying for a patent?

The meaning of patent lies in "publicity for protection", that is, the content of patent application will be known to the public, so misappropriation is inevitable. The first sentence of Article 1 of China's Patent Law points out that "patent is to protect the legitimate rights and interests of the patentee". Therefore, when the patent right is infringed, you can bring a lawsuit to the people's court according to law to safeguard your legitimate rights and interests. From the date of application to the end of the protection period, the legitimate rights and interests of the patentee are protected by the patent law. Articles 59 to 74 of the Patent Law and Articles 79 to 88 of the Detailed Rules are relevant laws related to the protection of patent rights, which can be consulted by themselves when necessary.