Neurological examination is mainly to understand whether protective sensation is still present. 1, 10 grams of nylon wire test: easy to use method, good repeatability, spend less money and time. ②Vibration Perception Threshold (VPT) test: Using the biothesiomter to measure the threshold at which the patient feels vibration, an elevated threshold indicates abnormal sensation. It can be assessed quantitatively. ③Nerve conduction velocity measurement: Usually the nerve conduction velocity of the peroneal nerve and its branches is measured, which is a more sensitive indicator of peripheral neuropathy. However, it is more expensive and the method is more complicated. 2, peripheral vascular examination: ① palpation of dorsalis pedis artery, posterior tibial pulsation: disappearance of dorsalis pedis artery and posterior tibial artery pulsation is an information of large vessel lesion. The method is simple and practical. ②Ankle artery-brachial artery blood pressure ratio (ABI): The degree of arterial patency and the site of stenosis or obstruction can be determined by measuring the blood pressure in different planes of the limb, which is a very valuable indicator of the vascular status of the lower limbs. ③. Oxygen partial pressure measurement (TcPO2): It reflects the tissue perfusion by measuring the oxygen content in the skin tissue, and TcPO2 decreases when the perfusion is reduced. Normal >40 mmHg, <30 mmHg indicates insufficient peripheral blood supply, and <20 mmHg predicts difficult wound healing. ④, Doppler detection of lower extremity blood flow: It has the advantages of two-dimensional ultrasound structural images, and at the same time can provide rich information on hemodynamics, easy and reliable. ⑤ CTA, MRA imaging: The application of CT or MRI can be imaged in three dimensions, reaching a high level of accuracy for vascular disease. Digital subtraction angiography: It can dynamically understand the degree and location of lower limb vascular occlusion and blood flow rate, and is still the "gold standard" for diagnosing diabetic foot vasculopathy. 3. Plantar pressure measurement: By measuring the pressure in different parts of the foot, gait analysis can be performed to understand whether the patient has pressure abnormalities and provide a basis for correction.