In order to solve the issues of heavy metal and polycyclic aromatic hydrocarbons contaminations in farmland in China,potted experiments were used to reveal the effects of eggplant straw based biochar(ESBC) combined with Ryegrass on the removals of heavy metal cadmium (Cd) and pyrene and soil microbial community structure.The aim of the present study was to clarify the mechanism of ESBC combined with Ryegrass remediating the Cd and pyrene co-contaminated soil.The results showed that under the soil Cd and pyrene contents of 16.8 mg/kg and 71.04 mg/kg,the removal rates of Cd and pyrene of the group with biochar reached 21.88% and 23.55% on the day 60 in soil,which was improved by 17.71% and 14.28% compared with the control group without biochar. When the biochar dosage and Ryegrass planting density were 30 mg/ g and 13.5 mg/cm² ,the highest Cd and pyrene removal rates were 20.59% and 70.58%,respectively.The high-throughput sequencing results showed that biochar could increase soil microbial abundance,and that biochar combined with Ryegrass could significantly affect soil microbial community structure.Cd-Pyrene contaminations decreased the relative content of dominant soil bacteria,in which the relative content of Sphingomonas and Gemmatimonas decreased by 3.08 pencentage points and 1.69 pencentage points;while biochar of the Cd resistant and pyrene degrading bacteria of Sphingomonas addition increased the relative content by 1.22 pencentage points;furthermore,biochar combined with Ryegrass could significantly increase the relative content of pyrene degrading bacteria Pseudomonas and Enterobacter by 160 times and 414 times.In summary,biochar combined with Ryegrass can significantly remove soil Cd and pyrene,and increase the relative abundance of Cd and pyrene degrading bacteria.