In order to investigate the remediation effect of the microbial-plant joint system on soil heavy metal Cd pollution, we carry out strain screening and pot experiment to explore the effects of plant growth-promoting bacteria on the accumulation capacity of ryegrass, soil physical and chemical properties and heavy metal speciation. The results show that the microscopic morphology of Burkholderia sp.YXL1 is pale yellow, rod-shaped and smooth edge with an average length of 5 μm, and it possesses strong growth-promoting ability and can tolerate cadmium content about 250 mg/L. The capacity of IAA production, siderophore and phosphate-solubilizing substances are 31.56 mg/L, 0.89 and 46.18 mg/L, respectively. In the <italic>YXL</italic>1-ryegrass joint remediation system, the organic matter and available phosphorus content in the soil are significantly increased by 4.08 g/kg and 2.54 mg/kg, respectively. The contents of weak acid extractable Cd and reducible Cd in the soil reach 16.25% and 12.53%, respectively. Compared with the control group, the ability of ryegrass to extract Cd from the soil is 2.76 times higher than that of the ryegrass treatment. The results also show that the Cd content of the cultivated layer soil is below the risk screening value (<0.3 mg/kg) in the Soil Environmental Quality Agricultural Land Soil Pollution Risk Control Standard (GB 15618—2018) to realize the safe use of agricultural land in the <italic>YXL</italic>1- ryegrass joint remediation system after 4 years.