In agricultural production systems, the harm of both antibiotics and microplastics (MPs) to human health has been an important and continuously concerned issue. A small bagged silage production system was designed to investigate the effects of Lactoplantibacillus plantarum, polyethylene (PE) -MPs and their mixture on the silage fermentation and chemical composition of Tetracycline (TET) -contaminated whole plant maize. In addition, the bacterial community of silage samples was analyzed by using next generation genome sequencing technology. The formation of an extremely acidic environment (pH <
3.8) by ensiling effectively promoted the degradation of tetracycline (about 12.36 ng/ml), with PE-MPs particles also cleaved from 100 μm to 10 μm (in diameter) after 60 days of anaerobic storage. The PE-MPs physically adsorbed TET through its special pore structure and interacted with silage fermentation-dominated microorganisms including Lacticaseibacillus with relative abundances of 33-95 %, where the combination of PE-MPs and L. plantarum degrades tetracycline to 7.05 ng/ml. The PE-MPs inclusion enhanced the fermentation function of Lacticaseibacillus and stabilized the pH, ammonia nitrogen and other chemical indices of silage mass. Importantly, the co-occurrence of PE-MPs sustained also the dominance of desirable Lacticaseibacillus at late stage of ensiling with TET-contaminated maize. Therefore, the combination of PE-MPs and L. plantarum counteracted undesirable silage fermentation from TET contamination, reduced hypothetically the risks to animal and even human health by unappreciated use of antibiotics in agricultural production system.