Abstract: The peanut gene AhGLK1 was heterologously expressed in glk1glk2 Arabidopsis mutants to explore its effect on the phenotypic characteristics and drought resistance of Arabidopsis thaliana. The phenotypic characteristics, including leaf color, leaf number and morphology of AhGLK1/glk1glk2 Arabidopsis line, were observed. The chloroplast was observed using a confocal microscope. The water loss rate and post-drought survival rate of AhGLK1/glk1glk2 were detected. The changes in chlorophyll fluorescence parameters of Arabidopsis leaves during drought and post-drought recovery were measured by using a uorescence detector. The results showed that the leaves of AhGLK1/glk1glk2 were green and curled, the petioles were prolonged, the chloroplasts developed well, the number of leaves was increased, and the number of stomata was increased. In addition, compared to glk1glk2, the water retention of the leaves and the survival rate after drought were significantly increased. Chlorophyll fluorescence parameters were significantly reduced under drought stress, but restored after recovery. AhGLK1 improves the drought resistance of Arabidopsis by affecting the number and morphological development of the leaf and its photosynthesis.