Aiming at the problem of large amount of redundant data in the remote transmission of vehicle data, a data remote transmission method based on deduplication was proposed. In the process of data remote transmission based on socket, firstly, the vehicle data to be transmitted was processed in blocks, and the eigenvalues of data blocks were calculated by MD5 algorithm. Then the calculated eigenvalues were packaged and sent to the ground receiving end, the data redundancy was judged by the ground receiving end. Aims at the characteristics of the data length was fixed but the period was different, a new method in data segmentation was put forward. Finally, the data of HX,D,2 locomotive was taken as an example to verify it. The experimental results showed that adding deduplication in wireless transmission could optimize transmission strategy, save network bandwidth and reduce data transmission cost.