Arbuscular mycorrhizal (AM) fungi can enhance the uptake of soil nutrients and water bycitrus, promoting its growth. However, the specific mechanisms underlying the action of AM fungiin promoting the growth of citrus were not fully elucidated. This study aimed to explore the role ofAM fungi Funneliformis mosseae in the regulatory mechanisms of P. trifoliata growth. Pot experimentscombined with non-targeted metabolomics methods were used to observe the growth process andchanges in metabolic products of P. trifoliata under the conditions of F. mosseae inoculation. Theresults showed that F. mosseae could form an excellent symbiotic relationship with P. trifoliata, therebyenhancing the utilization of soil nutrients and significantly promoting its growth. Compared with thecontrol, the plant height, stem diameter, number of leaves, and aboveground and underground dryweight in the F. mosseae inoculation significantly increased by 2.57, 1.29, 1.57, 4.25, and 2.78 times,respectively. Moreover, the root system results confirmed that F. mosseae could substantially promotethe growth of P. trifoliata. Meanwhile, the metabolomics data indicated that 361 differential metabolitesand 56 metabolic pathways were identified in the roots of P. trifoliata and were inoculated with F.mosseae. This study revealed that the inoculated F. mosseae could participate in ABC transporters byupregulating their participation, glycerophospholipid metabolism, aminoacyl tRNA biosynthesis,tryptophan metabolism and metabolites from five metabolic pathways of benzoxazinoid biosynthesis[mainly enriched in lipid (39.50%) and amino acid-related metabolic pathways] to promote the growthof P. trifoliata.