The plaintiff maliciously obtained the patent right and abused the patent right to conduct infringement litigation, which belongs to malicious patent litigation. Malicious acquisition of a patent right refers to an invention-creation that knows that it should not be protected by a patent, but deliberately circumvents the law or obtains it by improper means. In the determination of malicious litigation, whether the parties have subjective faults is the most critical issue, and its purpose is to obtain illegitimate interests or prevent others from legally implementing behaviors.