The study aimed to investigate the effects of different fungal residue substrate ratios on soil nutrients，rhizosphere bacterial communities，and yield in greenhouse cucumbers，thereby providing theoretical basis and technical support for the substrate utilization of fungal residues.Using greenhouse cucumber cultivar‘ Jindong 626’ as experimental material，three treatments were established:T1( fungal residue:peat moss:perlite = 10∶60∶30)，T2( fungal residue:peat moss:perlite = 20∶50∶30)，T3( fungal residue:peat moss:perlite = 30∶40∶30)，T4( fungal residue:peat moss:perlite =40∶30∶30)，and T5( fungal residue:peat moss:perlite = 50∶20∶30).These five compost-amended substrates were used to cultivate greenhouse cucumbers，with a commercial substrate serving as the control( CK).Changes in rhizosphere nutrient levels，enzyme activity，and bacterial community structure were measured.Comprehensive evaluations of the substrates were conducted based on cucumber root characteristics，growth development，fruit quality，yield，and economic benefits.Illumina MiSeq high-throughput sequencing technology was employed to investigate changes in bacterial community structure within the rhizosphere of cucumbers under each treatment.Nutrient levels in the compost-amended substrates differed significantly from CK.Bulk density，pH，and total nitrogen content increased significantly in the compost-amended substrates，along with alkaline phosphatase and urease activity.Treatment T3 exhibited significantly higher alkalinehydrolyzable nitrogen content，sucrase activity，total root length，total root surface area，total root volume，root vitality，bacterial community richness and diversity in the cucumber rhizosphere，plant height，stem diameter，lateral stem number，singht fruit weight，yield per plant，yield per hectare，soluble protein content，and vitamin C content than other treatments.Through comprehensive membership function analysis，the ranking of composite substrates was determined as T3 > T2 > T4> T5 > T1 > CK.The optimal composite substrate ratio for greenhouse cucumber cultivation was fungal residue:peat moss:perlite = 30∶40∶30( T3)，which could promote cucumber growth and enhance fruit quality.