The purpose of this experiment was to explore the effects of Melatonin (MT) application in the rhizosphere, inoculation of Claroideoglomus etuncatum and its combined treatment on the growth, chlorophyll fluorescence parameters, hormone metabolism and antioxidant system of rose seedlings under 100 mol/L salt stress, so as to explore the mechanism of both alleviating the salt stress of rose. The results showed that under salt stress, the growth of rose seedlings was inhibited, and plant height, stem diameter, and biomass significantly decreased; The application of MT can promote AMF infection, increase the infection rate, clump growth rate, number of vesicles, and number of invasion points. Under 100mol/L salt treatment, compared with the control (CK) treatment, the total chlorophyll content and chlorophyll a/b of AMF+MT treatment increased by 46.2% and 67.2%, respectively; The maximum photochemical efficiency (Fv/Fm), potential activity (Fv/Fo), and actual photochemical efficiency of PS II in chlorophyll fluorescence parameters(φPSII), PSII effective photochemical quantum efficiency (Fv "/Fm"), and photochemical quenching coefficient (qP) increased by 4.9%, 51.0%, 175.0%, 168.7%, and 92.5%, respectively, with a decrease in NPQ of 42.7%; In addition, under salt stress, the contents of zeatin nucleoside (ZR), gibberellin (GA), and auxin (IAA) in rose leaves decreased, while the content of Abscisic acid (ABA) increased. After AMF+MT treatment, ZR, GA, and IAA increased by 146.9%, 116.9%, and 35.7%, respectively, and ABA decreased by 21.1%; At the same time, AMF+MT treatment can activate the activities of antioxidant enzymes SOD and CAT, reduce the rate of superoxide anion (O2-) production and H2O2 accumulation. The conclusion is that the inoculation of AMF, the addition of MT or AMF+MT can increase the chlorophyll content, protect the chlorophyll fluorescence system, maintain the balance of plant endogenous hormones, activate the activities of SOD, CAT and other antioxidant enzymes, and reduce the accumulation of Lipid peroxidation and H2O2, so as to alleviate the damage of salt stress to the monthly seedlings and promote the growth of roses. The effect of AMF+MT treatment on the salt resistance of rose seedlings is better.