Article 24 An invention-creation applying for a patent shall not lose its novelty in any of the following circumstances within six months before the date of filing:
(1) It was exhibited for the first time at an international exhibition sponsored or recognized by the China Municipal Government;
An international exhibition recognized by the China government as mentioned in Item (1) of Article 24 of the Patent Law refers to an international exhibition registered or recognized by the Bureau of International Exhibitions as stipulated in the Convention on International Exhibitions.
In practice, if you can't get the exhibition certificate, or the exhibition you participated in is not required by laws and regulations, you should directly apply for protection technology, because others want to invalidate your patent through public exhibition, and you need to issue strict judicial evidence to prove that you have indeed publicized the exhibition before applying.