Abstract: Based on the multi- point measurements,the refractive index is fitted from the data of non- least deviation angular by the nonlinear- fitting of Origin（ software）,to gain the dispersion relation of sample. The multiple point measuring method can be used to improve the degree of accuracy of dispersion relation of sample and achieve higher precision measurement than the least deviation angular method,by comparing multiple point measuring method and the least deviation angular method of fitting results of dispersion equation.

Key words: multi-point measuring and fitting method, least deviation angular, refractive index, nonlinear-fitting, dispersion relation