Peanuts easily go moldy under unsafe storage conditions， reducing their edible quality. In order to seek for safe and effective anti-mildewing methods for peanuts' storage， the antifungal activity of plant essential oils from cinnamon， litsea cubeba， clove， citronella and thyme against advantage molds of moldy peanuts was investigated in this study. At first， a mold strain， BQM， was isolated from moldy peanuts. The strain BQM was identified by morphological characters combined with 18S rRNA sequence analysis. Then the antifungal effects of five kinds of single plant essential oil and their mixtures on BQM were evaluated by the inhibition zone test. The composition of the mixed oils with best antifungal effect was also determined. Finally， the effect of mixed oils on the mycelia of BQM was observed under scanning electron microscope. The results indicated that： the mold strain BQM was identified as Aspergillus niger； the cinnamon-litsea cubeba mixed essential oil displayed the best antifungal effect on Aspergillus niger BQM and the minimum inhibitory concentration （MIC） was 0.125 μL/mL， and the best ratio of essential oil was determined as cinnamon ∶ Litsea cubeba = 3 ∶ 5； the pictures of scanning electron microscope showed that the morphology of mycelia treated by cinnamon-litsea cubeba mixed essential oil was seriously damaged and the deformation phenomena such as shrinking， shrivelling and sinking occurred. Therefore， cinnamon-litsea cubeba mixed oil may have great potential for peanut anti-mildewing due to its effective antifungal activity against Aspergillus niger BQM.