Nowadays, the measurement of generalized ECG is a 12-lead system, and the measurement steps can be divided into treating the skin, placing the electrodes, tracing and marking. 1. Handle the skin: apply alcohol, saline or conductive gel on the upper 7cm of the two inner ankles and about 3cm above the flexion side of the two wrist joints. 2. Placement of electrodes: limb leads were placed in the order of red, yellow, green and black from the right upper limb to the right lower limb; chest leads V1~V6 were placed in the order of red, yellow, green, brown, black and purple in accordance with their corresponding positions. 3. Tracing: Turn on the power, generally choose the paper walking speed is 25mm/s, start to record the ECG. 4. Marking: Record the corresponding name, gender and other information on the ECG paper. Measurement of ECG needs to pay attention to some details, such as taking rest before measurement, preventing the electrodes from being placed in the wrong position during measurement, and the adsorption time should not be too long so as not to damage the skin and so on. For details, please consult your physician for advice.