Abstract: An angular surface plasmon resonance measurement system based on prism was designed. The mechanical structure with coaxial double layer rotating table was setup. We proposed a novel scanning angular measurement method and obtained the surface plasmon resonance curve. The impact factors on the consistency of multiple measurements were studied, the new method decreased the measuring point number, increased the sample data on one point, and used three kinds of variable steps. The measurement time was decreased to 1/10, and the precision reached 4E-5 refractive index level from 1E-4 refractive index level.