Microwave sensing technology has become increasingly widely applied in the biomedical field, playing a significant role in medical diagnosis, biological monitoring, and environmental warning. In recent years, the introduction of metamaterials has brought new possibilities and opportunities to microwave biosensors. This paper aims to explore the applications of microwave sensors in biosensing, with a particular emphasis on analyzing the crucial role of metamaterials in enhancing sensor performance and sensitivity. It provides a thorough examination of the fundamental principles, design strategies, fabrication techniques, and applications of microwave biosensors leveraging metamaterial enhancement. Moreover, it meticulously explores the latest applications spanning biomedical diagnostics, environmental monitoring, and food safety, shedding light on their transformative potential in healthcare, environmental sustainability, and food quality assurance. By delving into future research directions and confronting present challenges such as standardization and validation protocols, cost-effectiveness and scalability considerations and exploration of emerging applications, the paper provides a roadmap for advancing microwave biosensors with metamaterial enhancement, promising breakthroughs in multifaceted bioanalytical realms.