Abstract: In the coal mining area of the Loess Plateau,the climate is arid,the soil quality is poor,and the farmland output is low.To explore inoculated Arbuscular Mycorrhizal Fungi(AMF) under drought stress after the soil moisture change and its influence on plant phenotypic structure,with peanut as the research object,setting field pot exper iment,this study had conducted two kinds of test,i.e.,under drought and bacterial inoculation conditions.In the tests,the EM50 soil humidity monitoring system was used for real time monitoring soil moisture changes in salt,and in the middle of plant growth,the 3 d laser scanning technology and CI-690 ROOTSNAP root analysis software system were used to measure their canopy structure characteristic and root phenotype.The results showed as follows:① under drought stress,the infection rate of root mycorrhiza decreased by 62.8% compared with normal conditions.② Fungi culture enhanced soil water retention.The results showed that the normal inoculation treatment was greater than the drought inoculation treatment,the drought inoculation treatment was greater than the normal control treatment,and the normal control treatment was greater than the drought control treatment.③ The plant canopy structure was changed by inoculation,and the projected area,number of leaves,total area of leaves,average upper leaf area and flowering number of peanut under normal+AMF treatment were increased by 6.0%,13.0%,7.5%,13.9% and 22.7%,respectively,compared with normal control treatment,while those under drought+AMF treatment were increased by 37.0%,13.2%,38.0%,26.0% and 57.0%,respectively.④ The inoculation changed the root traits and increased the proportion of coarse and fine roots of peanut,and the root characteristics of normal+AMF treated plants were that the roots longer than 1 mm and 0.8-1.0 mm accounted for 9.38% and 18.27%,while those of normal control treatment accounted for 2.7% and 13.6%,respectively.In drought treated and AMF treated plant roots,the roots longer than 0.8 mm and shorter than 0.6 mm accounted for 26.7% and 25.2%,respectively,while drought control treatment accounted for 8.1% and 15.7%,respectively.④ The root phenotype was significantly correlated with the canopy phenotype.Total root volume,mean root diameter and leaf number were positively correlated with the correlation coefficients of 0.60 and 0.66,respectively (P