In order to establish a rapid，simple and new analysis method for determination of fluorine content and its distribution in peanut.With peanut as the samples from Xinyang and dengzhou city respectively，The Determination of fluoride ion by selective electrode with direct reading concentration method，after samples were extracted with ultrasonic.The results show that Conversion factor of fluorine electrode was 90.53%，relative standard deviation RSD＜4.1% based on the Samples parallel determination（n=5），and Standard addition recovery was 91.6%~101.0% between.The fluorine distribution is reduced from outside to inside in peanut.Xinyang dry base peanut fluorine content lowest is 0.52 μg/g.This method can complete within 2 h，At the same time with fast，convenient and practical，less environmental pollution，suitable for mass rapid determination.