The “Guidelines for diagnosis and treatment of groin hernia in adults (2018 edition)” was completed on the basis of the previous edition by the joint discussion and consultation of more than 50 experts and scholars in China, after making an overview of the related etiology, pathology, classification and typing of groin hernia across the world, and combined considerations of the clinical practice in our country. In the current edition, the diagnosis, differential diagnosis, surgical treatment and other aspects of inguinal hernia are systematically expounded, and the viewpoints, measures and methods supported by evidence-based medicine are also pointed out. The relevant medical institutions and professionals in China are requested to use this document as a reference in clinical practice.