The so-called compulsory license means that under special legal conditions, others can obtain the license to exploit the patent after completing the legal procedures without the consent of the patentee, but they should still pay the patentee the patent exploitation license fee.
According to Article 48 of China's Patent Law,
Under any of the following circumstances, the administrative department for patent in the State Council may grant a compulsory license to exploit a patent for invention or utility model upon the application of a unit or individual with the implementation conditions:
(1) It has been three years since the patent right was granted and four years since the patent application was filed, and the patentee has not implemented or not fully implemented his patent;
(2) The patentee's act of exercising the patent right is recognized as a monopolistic act according to law, so as to eliminate or reduce the adverse effects of the act on competition.
Article 49 In case of national emergency or extraordinary circumstances, or for the purpose of public interest, the patent administration department in the State Council may grant a compulsory license to exploit a patent for invention or utility model.
Article 50 For the purpose of public health, the patent administration department in the State Council may grant compulsory licenses for the manufacture and export of patented drugs to countries or regions that meet the requirements of relevant international treaties to which People's Republic of China (PRC) is a party.
Article 51 Where a patented invention or utility model is a major technological progress with great economic significance compared with the patented invention or utility model before, and its implementation depends on the implementation of the previous invention or utility model, the patent administration department in the State Council may grant a compulsory license to exploit the previous invention or utility model upon the application of the latter patentee.
Where a compulsory license is granted in accordance with the provisions of the preceding paragraph, the administrative department for patent in the State Council may also grant a compulsory license to exploit the latter invention or utility model upon the application of the former patentee.
I hope my answer is helpful to you. O(∩_∩)O