The neurological examination focuses on understanding whether protective sensation is still present. 10 grams of nylon wire test: easy to use method, good repeatability, spend less money and time. 1. Vibratory perceptual threshold (VPT) test: The biothesiomter is used to measure the threshold at which the patient feels vibration, and an elevated threshold indicates abnormal sensation. It can be assessed quantitatively. 2, nerve conduction velocity measurement: usually determine the nerve conduction velocity of the peroneal nerve and its branches, is a more sensitive indicator of peripheral neuropathy. However, it is more expensive and the method is more complicated. Peripheral vascular examination: (1) palpation of dorsalis pedis artery and posterior tibial pulsation: loss of pulsation of dorsalis pedis artery and posterior tibial artery is an information of large vessel lesion. The method is simple and practical. (2) Ankle artery-brachial artery blood pressure ratio (ABI): By measuring the blood pressure in different planes of the limb, the degree of arterial patency and the site of stenosis or obstruction can be determined, which is a very valuable indicator of the vascular status of the lower limbs. (3) Oxygen partial pressure measurement (TcPO2): The oxygen content in the skin tissue is measured to reflect the tissue perfusion, 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 nuclear magnetic examination can be three-dimensional imaging, reaching a high level of accuracy for vascular disease. (6) 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 the diagnosis of diabetic foot vasculopathy. (4) 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.