Abstract: In view of the underground wireless mobile node localization algorithm, on the basis of energy calculation localization algorithm, three-point localization is designed based on adaptive classification. Algorithm will classify energy distance information of N points collected from any single point by using the method of sorting. Strong characteristic data have been retained in a similar class, and three location points with strong features were adaptively selected. Finally, the exact position of the target is calculated by three letters punctuation localization algorithm. We simulated the effect of these two important parameters of minimum response power and path loss coefficient on energy calculation, and carried out locating test for three unknown target nodes under different environment. Ranging results show that the accuracy is reduced with the increase of distance ranging. Ranging error is less than 4% within 100 m range. After three-point localization algorithm analysis and calculation, the error of the measured target coordinate and the real target position is less than 1 m.