Aluminum toxicity constitutes a critical environmental constraint limiting plant productivity in acid soils. Ectomycorrhizal fungi (ECMF) can mitigate Al-induced stress and promote root growth in Pinus massoniana (masson pine), but the molecular and metabolic underpinnings are unclear. This study presented a comprehensive analysis of transcriptional, metabolic, and hormonal alterations in P. massoniana roots inoculation with Lactarius deliciosus ( Ld 2) under 1.0 mM Al ³⁺ stress. Results showed the symbiotic system activated phenylpropanoid biosynthesis pathway, facilitating L-fucose accumulation in cell walls and upregulating Al transporter gene XTH31, thereby enhancing extracellular sequestration through cell wall remodeling. Concurrently, symbiotic roots exhibited significant reductions in osmoprotectants including carbohydrates, amino acids, organic acids, and flavonoids, accompanied by hormonal reconfiguration featuring elevated salicylic acid/gibberellin levels and decreased jasmonate content. Molecular regulation analysis revealed Ld 2-induced upregulation of growth-related genes ( MYC2, GH3, TCH4) alongside suppression of COI1, ARF9/19, and DELLA genes, while stress-responsive markers ERF1/2, ABF, and PR-1 showed marked activation. The dual adaptation strategy combines cell wall reconstruction for enhanced physical barriers with metabolic reprogramming and hormone crosstalk-mediated physiological adjustments, providing valuable insights for the application of plant-mycorrhizal symbioses in ecological restoration and afforestation endeavors.