Abstract: Crohn's disease (CD) is a chronic inflammatory bowel disease with complicated pathogenesis and prolonged condition. In recent years, with the development of targeted therapy, biological agents have been widely used in the treatment of CD, which has significantly improved the prognosis of CD patients. If the efficacy evaluation can be carried out at the early stage of targeted therapy, it may help to figure out the patients who can benefit from the treatment and optimize the treatment plan for the ineffective patients in time. In the evaluation of CD activity and efficacy, ultrasound has the advantages of high accuracy, no radiation and high patient acceptance, and therefore has potential clinical application value in the early efficacy evaluation of CD targeted therapy. This article reviews the research progress to provides a reference for optimizing the treatment plan for CD patients.