Various business relationships and routing policies exist among the autonomous systems (ASes) in an inter-domain routing system. Routing propagation violating the export policy agreements among the ASes is likely to cause route leaks, ultimately leading to serious consequences such as network interruption, traffic eavesdropping, and link overload. Verifying routing policy compliance is thus essential for ensuring the security and stability of the inter-domain routing system. However, the dual requirements of ASes for the autonomous configuration and privacy protection of local routing policies increase the difficulty in verifying routing policy compliance and consequently pose a hard problem that remains to be settled properly in the field of inter-domain routing security. This study proposes a blockchain-based verification method for inter-domain routing policy compliance. With blockchain and the cryptographic technology as trust endorsements, this method enables ASes to publish, interact, verify, and execute routing policy expectations in a safe and private manner. The authenticity of the routing propagation process is ensured by generating route attestations corresponding to routing updates. Thus, the verification of routing policy compliance is completed by multi-domain cooperation. A prototype system is implemented, and experiments and analyses are carried out on real routing data. The results show that the proposed method offers traceable verification of export policy compliance of routing propagation without leaking the business relationships and local routing policies among ASes, suppresses policy-violating routing propagation effectively with reasonable overhead, and maintains a remarkable ability to suppress policy-violating routing even in partial deployment scenarios.