Abstract: In order to explore the effects of conventional plastic mulch and biodegradable plastic mulch on the soil properties and the quality of cured tobacco. A randomized block tests were designed in the field, the treatments: conventional plastic mulch (PM) and biodegradable plastic mulch (BPM), and a control treatment of no mulch (CK). Using scanning electron microscopy and high-throughput sequencing, the effects of different plastic mulch treatments on soil microplastic content, soil properties, bacterial communities, as well as the effects of tobacco quality. The results showed that PM treatment increased the residue of microplastics in non-rhizosphere soil, while BPM treatment mainly increased the residue of microplastics in rhizosphere soil. Analysis of soil nitrogen content and enzyme activity showed that biodegradable plastic mulch significantly increased the total nitrogen content and regulated soil enzyme activity. Principal co-ordinates analysis (PCoA) indicated that mulching significantly affected the structure of bacterial communities in non-rhizosphere and rhizosphere soil, increased the richness index of soil bacterial communities, and reduced community diversity. In terms of tobacco quality, mulching significantly improved the tobacco quality, while BPM treatment significantly increased the potassium content of tobacco leaves and the total amount of neutral aromatic substances in cured tobacco leaves. The study shows that different mulching methods have a significant impact on the distribution and relative abundance of soil microplastic residues. At the same time, biodegradable plastic mulch has a potential advantage in improving tobacco quality, providing experimental basis for the biodegradable plastic mulching. However, further research is needed to explore the long-term ecological effects of microplastic residues and their comprehensive impact on tobacco growth.