With the escalating severity of cybersecurity threats， Distributed Denial of Service （DDoS） attacks remain a persistent challenge in network security research. Traditional DDoS protection solutions usually rely on centralized architectures， which suffer from single point of failure， data tampering and other problems， and are difficult to deal with complex and diverse attack scenarios. Blockchain technology provides a new solution for DDoS protection with its characteristics of decentralization， immutability and transparency. In view of the technical challenges in DDoS protection， the progress of blockchain-based DDoS protection was summarized. Firstly， the basic concepts of DDoS attacks and their threats to environments such as traditional networks， Internet of Things （IoT） and Software Defined Networking （SDN） were introduced， and the necessity and potential advantages of introducing blockchain technology were analyzed. Secondly， from the aspects of blockchain combined with smart contracts， deep learning， cross-domain collaboration， and so on， the existing DDoS protection mechanisms were reviewed and compared. Finally， considering the technical difficulties in blockchain performance optimization， multi-domain collaboration， and real-time response， the future development directions of blockchain-based DDoS protection technology were prospected， providing theoretical references for researchers in the field of cybersecurity and further promoting the practical applications of blockchain in DDoS protection.