The invention relates to a method for low-overhead data transmission of a distributed file system based on a Fat-B tree. According to the method, a low-overhead log module, a low-overhead committing protocol and a failure recovery module are included. An abutting pre-writing log policy capable of effectively reducing overhead of a log in the transaction processing and submitting process is adopted for the low-overhead log module; the low-overhead committing protocol is a submitting transaction protocol which adopts a Fat-B tree index message queue and optimizes overhead in the submitting process; and a policy supporting host failure and queue failure recovery is adopted for the failure recovery module. A Fat-B tree index structure is utilized to establish a message queue mechanism of the distributed file system, and the asynchronous abutting pre-writing log policy suitable for the distributed file system is given; on the basis, the low-overhead data transmission submitting transaction protocol suitable for the distributed file system is provided, and thus the communication overhead in the transaction processing process of the distributed file system is effectively reduced.