There are several possible causes of knee pain when walking in the elderly: first, degenerative osteoarthritis in the elderly, which can lead to damage to the knee cartilage and secondary damage to the meniscus, resulting in knee pain when walking, and early diagnosis and treatment by taking x-rays and CT of the knee. Second, knee goosefootitis, knee goosefootitis is often pain on the inside of the knee joint, the pain is more significant when walking or cold, strain, then early examination and MRI of the knee joint to early diagnosis and early treatment. Third, patellofemoral osteoarthritis, patellofemoral osteoarthritis can be serious when walking with significant pain in the knee, often caused by the degeneration of the patellofemoral cartilage, it is necessary to take early X-ray and MRI of the knee joint for early diagnosis and early treatment.