Inclusion Criteria:  Understand the study procedures and methods, voluntarily participate in the study, and sign the written informed consent form (ICF); Scheduled to undergo elective unilateral total knee arthroplasty; Males or females aged 40-75 years.  Exclusion Criteria:  Weighing less than 40 kg or greater than 135 kg; Allergic to contrast agents rendering the patient unable to undergo venous angiography of the lower extremities; allergic to enoxaparin or any of the ingredients listed in the package insert thereof; allergic to the investigational product or any of the ingredients thereof; With malignant tumors that still require medical intervention; except for radically treated non-melanoma skin cancer, basal cell carcinoma or squamous cell skin cancer, or cervical carcinoma in situ; With a history of major liver disease within 1 year; With myocardial infarction, transient ischemic attack, or ischemic stroke within 6 months.