Abstract: Maintaining the postharvest quality of fruits and vegetables is crucial for a healthy diet, as microorganisms present during harvesting, transportation, and storage can accelerate decay. Quality deterioration in fruits and vegetables occurs irreversibly due to the interaction of physiological changes, environmental factors, and pathogens. With growing awareness of health and safety, green preservation technologies are vital for controlling the deterioration. Bacillus spp. are Gram-positive bacteria that can produce antimicrobial peptides, organic acids, and other metabolic products, exhibiting broad antibacterial and antifungal activities. They are valuable resources for new natural antimicrobial drugs. Bacillus spp. is a promising source of natural antibiotics and biocontrol agents due to their antimicrobial properties, ability to produce endospores, and resilience to high temperatures and droughts. This study provides a comprehensive summary of how Bacillus spp., along with their volatile and non-volatile metabolites, inhibit pathogens and extend storage duration. The mechanisms by which Bacillus spp. prevent pathogen proliferation and induce plant disease resistance are analyzed focusing on their biocontrol effects. Additionally, the application of Bacillus spp. in the post-harvest preservation of fruits and vegetables is reviewed, and potential future research directions are proposed. Overall, this paper offers a theoretical framework for the investigation and application of Bacillus spp. in the prevention of postharvest diseases, as well as in the enhancement of fruit and vegetable storage quality.