For your question, first of all, from the patent application, the patent application must be novel, creative and practical. To put it simply, your patented technology is a new invention, which was not available before. At the same time, it has made remarkable progress compared with the previous technology, and finally it has to be used for mass production. So when you apply, you will compare these conditions on a global scale, which is called retrieval.
Then, after searching, some places may give you a report, which will explain whether your technology is novel and creative, and at the same time explain the comparative literature closest to your technology. Whether it is in Chinese or English depends on the specific situation.