Research on DeFi (Decentralized Finance) security focuses on identifying and mitigating vulnerabilities in blockchain-based financial platforms that operate without centralized intermediaries. Key concerns include smart contract bugs, flash loan attacks, oracle manipulation, and protocol exploits, which can lead to significant financial losses. Researchers analyze transaction flows, perform formal verification of smart contracts, and develop intrusion detection and anomaly detection mechanisms to enhance platform resilience. Additionally, approaches such as multi-signature wallets, decentralized governance, and automated security audits are explored to reduce risks and improve trustworthiness. Overall, advancing DeFi security is critical to ensuring safe, reliable, and scalable financial services in decentralized ecosystems.