The brachialankle pulse wave velocity (baPWV) is usually used as an evaluation index of the elasticity of the blood vessel wall, the commonly used measurement method of baPWV is the method of extremity brachial and ankle polyconduction signals. Aiming at the problem of expensive detection instrument and complex operation, a new method is proposed to detect the degree of arteriosclerosis by collecting the photoelectric volume pulse wave at the fingertip. Clustering analysis is carried out by using independent pulse pressure index P1 and P2 combined with the characteristic parameter K value, which has correlation with the elasticity of the vessel wall. By improving K_means algorithm to select representative waveforms in several waveform cycles, the characteristic parameters are extracted for regression modeling by support vector machine. The results show that the average absolute relative deviation of the detection value is 421%. This results indicating that this method is a simple and effective method for the detection of vessel wall elasticity, which fully meets the actual clinical application requirements.