The use of photoelectricity is a constant sensor pulse signal of human body. The tissue with constant wave length on the fingertip can be divided into two parts: the tissue with non blood intensity and the tissue with non blood intensity, such as skin and bone. The tissue absorption caused by the fluctuation of non blood group is very tiny light, while the extraction of venous blood in the blood is relatively weak compared with the light pulse blood of the indirect finger It can be ignored that there are no muscles or meters, so the blood group can only measure the changes of the human body after passing through the fingers for the light of arterial blood in a light source fabric, and then under the irradiation, the pulse information can be obtained by measuring the light