The invention discloses a blockchain-based intrusion detection system for railway signal, which is built on a blockchain's distributed chain structure, without a central, trusted control center. This design mitigates the vulnerabilities associated with centralized intrusion detection centers. Additionally, by utilizing a blockchain-based distributed structure, it also eliminates the risk of a single point of failure for the intrusion detection center. Moreover, the data within the blockchain-based intrusion detection system is highly resistant to malicious tampering. This is achieved by leveraging the consensus mechanism inherent in the blockchain, which can achieve consensus among intrusion detection nodes. The current invention solves the internal evil attacks and avoid the inability to reach consensus between nodes due to internal evil, thereby affecting the intrusion detection performance; at the same time, the intrusion detection model can resist external network attacks.