The backward of peanut protein was studied by AOT (sodium bis-(2-ethylhexyl) sulfosuccinate)/isooctane reverse micelles system from full-fat peanut powder with sonication. The main factors effecting reverse micelles extraction were analyzed. The orthogonal test design results showed that the optimum conditions of backward extraction were pH 8.5, extraction time 40 min, temperature 40 ℃, ultrasonic power 240 W, and KCl concentration 1.5 mol/L, under which the extraction rate was 82.17±1.52%.