A new architecture that supports multiple coordinators and multi-replica storage has emerged in distributed database systems, which brings new challenges to the correctness of transaction scheduling. The challenges are represented by new data anomalies caused by the lack of a central coordinator and data inconsistency caused by the multi-replica mechanism. Based on the definition of transaction isolation levels and consistency protocols for distributed systems, this study constructs a unified hybrid dependency graph model for transactional multi-level consistency in multi-coordinator and multi-replica distributed databases. The model provides a robust standard for evaluating the correctness of transaction scheduling, which can facilitate dynamic or static analysis of transaction scheduling in databases.