Abstract: This paper uses equal amount of deflection to obtai n p rimitive experimental data, uses the least square method p rincip le to p rocess galvanometer, obtain sensitive galvanometer’s two basic parameters such as cur2 rent sensitivity and interface resistance, and compareswith the result gained by the direct graphic method. The re2 sults show that the experimental data p rocessed by the least square method are more accurate than the data p ro2 cessed by direct graphic method.