The present disclosure provides a parallel decision system and method for distributed data processing. The system includes: an initial logical node generation assembly, a logical node traversal assembly, a predetermined configuration cost computation assembly, and a parallel decision assembly. The initial logical node generation assembly is configured to receive task configuration data input by a user to generate an initial logical node topology for the distributed data processing system. The logical node traversal assembly is configured to traverse the initial logical node topology to obtain a predetermined configuration in the initial logical node topology. The predetermined configuration cost computation assembly is configured to compute a transmission cost of each predetermined configuration and a cost sum. The predetermined configuration transformation assembly is configured to, based on the result of the predetermined configuration, reduce an initial logical node, and a connection edge, a combined initial logical node.